Contents

#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <iostream>
#include <algorithm>
#include <set>
using namespace std;
#define Lson(x) (x<<1)
#define Rson(x) (x<<1|1)
#define Mid(x,y) ((x+y)>>1)
#define MAXN 10010

int pos;
set <int> s;
//n的上限是1万，num存区间，所以上限是2n，temp存离散化后的数组，上限是4n(因为可能都相差大于1，就是num的两倍了),
//又因为要把temp复制回num数组，所以num也开4n，线段树就要开4*4n，但杭电给的数据好像没有这么恶心，似乎没有到达这个极限，
//所以我用线段树开8n也水过了  
//300MS左右，我师傅的版本是79MS
//set可以改为用数组，二分查找用c++库里自带的 速度就应该会提上来的
int num[4 * MAXN];
int temp[MAXN * 4];
//vis[MAXN], ans[MAXN * 4];

struct Node{
    int left;
    int right;
    int mark;
}node[MAXN * 16], tmp[16 * MAXN];

void hash_s(){

    int index = 1;
    for(int i = 0; i < pos; i++){
        temp[index++] = num[i];
        if(num[i+1] - num[i] > 1)
            temp[index++] = num[i] + 1;
    }
    pos = index - 1; //pos从 1 开始
    memcpy(num, temp, sizeof(num));
    //for(int i = 1; i <= pos; i++)
        //printf(":: %d\n", num[i]);
}

int Search(int x){
    int left , right , mid;
    left = 1 , right = pos;
    while(left <= right){
        mid = (left+right)>>1;
       if(num[mid] == x)
           return mid;      //在这里通过mid离散化为num里的值离散化为num的序列
       else if(num[mid] < x)
           left = mid+1;
       else
           right = mid-1;
    }
}

void push_down(int pos){

    if(node[pos].mark){
        node[Lson(pos)].mark = node[pos].mark;
        node[Rson(pos)].mark = node[pos].mark;
        node[pos].mark = 0;
    }
}

void build_tree(int left, int right, int pos){

    node[pos].left = left;
    node[pos].right = right;
    node[pos].mark = 0;
    if(left == right)
        return ;
    int mid = Mid(left, right);
    build_tree(left, mid, Lson(pos));
    build_tree(mid + 1, right, Rson(pos));
}

void update(int left, int right, int value, int pos){

    if(left <= node[pos].left && node[pos].right <= right){
        node[pos].mark = value;
        return ;
    }
    push_down(pos);
    int mid = Mid(node[pos].left, node[pos].right);
    if(right <= mid)
        update(left, right, value, Lson(pos));
    else if(left > mid)
        update(left, right, value, Rson(pos));
    else{
        update(left, mid, value, Lson(pos));
        update(mid + 1, right, value, Rson(pos));
    }
}

int query(int left, int right, int pos){

    if(node[pos].left == node[pos].right){
        return node[pos].mark;
    }

    push_down(pos);

    int mid = Mid(node[pos].left, node[pos].right);
    if(right <= mid)
        return query(left, right, Lson(pos));
    else
        return query(left, right, Rson(pos));
}

int main(){

    freopen("input.txt", "r", stdin);
    int T, n;
    scanf("%d", &T);
    while(T--){
        scanf("%d", &n);
        pos = 0;
        for(int i = 1; i <= n; i++){
            scanf("%d%d", &tmp[i].left, &tmp[i].right);//先保存最初的区间
            num[pos++] = tmp[i].left, num[pos++] = tmp[i].right;
        }
        sort(num, num + pos);
        pos = unique(num, num + pos) - num;//忽略重复的，pos是从0开始的
        hash_s();
        for(int i = 1; i <= n; i++){
            tmp[i].left = Search(tmp[i].left);//把区间改为离散化后的区间
            tmp[i].right = Search(tmp[i].right);
            //printf("%d %d\n", tmp[i].left, tmp[i].right);
        }
        build_tree(1, pos, 1);
        //printf("pos: %d\n\n",pos);
        for(int i = 1; i <= n; i++)
            update(tmp[i].left, tmp[i].right, i, 1);

        s.clear();
        for(int i = 1; i <= pos; i++)
        {
            int x = query(i, i, 1);
            if(x != 0)// 注意，这里空的区间则mark为最初的0，说明没有贴海报，这一段就不应该算入
                s.insert(query(i, i, 1));
        }
        /*set<int>::iterator it;        for(it = s.begin(); it != s.end(); it++)            printf("wo :: %d ", *it);// 中间空着的是0*/
        for(it = s.begin(); it != s.end(); it++)
            printf("wo :: %d ", *it);// 中间空着的是0*/

        printf("%d\n" , s.size());

        /*int index = 1, x;        memset(vis, 0, sizeof(vis));        for(int i = 1; i <= pos; i++){            x = query(i, i, 1);            printf("xx %d\n ", x);            if(!vis[x] && x != 0){                vis[x] = 1;                ans[index++] = x;            }        }        for(int i = 1; i <= index - 1; i++)            printf("ans:: %d ", ans[i]);        printf("x :: %d", x - 1);*/
        memset(vis, 0, sizeof(vis));
        for(int i = 1; i <= pos; i++){
            x = query(i, i, 1);
            printf("xx %d\n ", x);
            if(!vis[x] && x != 0){
                vis[x] = 1;
                ans[index++] = x;
            }
        }
        for(int i = 1; i <= index - 1; i++)
            printf("ans:: %d ", ans[i]);
        printf("x :: %d", x - 1);*/

    }
    return 0;
}


/**输入：251 40000002000000 60000008000000 100000003000000 40000007000000 1000000051 42 68 103 47 10输出：44*/
*输入：
2
5
1 4000000
2000000 6000000
8000000 10000000
3000000 4000000
7000000 10000000
5
1 4
2 6
8 10
3 4
7 10

输出：
4
4
*/

//////////////////////////////////////////////////////////////////////////////


#include <cstdio>
#include <cstring>
#include <algorithm>
#define N 10005

using namespace std;

int tree[N << 4], n, maxs, tmp[N << 2], tmpsz;
bool mark[N];

struct qu
{
    int l, r;
} arr[N];

inline void init(){

    memset(tree, tmpsz = 0, sizeof(tree));
    memset(mark, false, sizeof(mark));
    mark[0] = true;
}

void update(int ll, int rr, int val, int l = 1, int r = maxs, int i = 1){

    if (ll <= l && rr >= r)
    {
        tree[i] = val;
        return;
    }
    if (tree[i])
    {
        tree[i << 1] = tree[i << 1 | 1] = tree[i];
        tree[i] = 0;
    }
    int m = (l + r) >> 1;
    if (m >= ll)
        update(ll, rr, val, l, m, i << 1);
    if (m < rr)
        update(ll, rr, val, m + 1, r, i << 1 | 1);
}

int query(int l = 1, int r = maxs, int i = 1){

    if (l == r)
    {
        if (!mark[tree[i]])
        {
            mark[tree[i]] = true;
            return 1;
        }
        return 0;
    }
    if (tree[i])
    {
        tree[i << 1] = tree[i << 1 | 1] = tree[i];
        tree[i] = 0;
    }
    int m = (l + r) >> 1;
    return query(l, m, i << 1) + query(m + 1, r, i << 1 | 1);
}

int main(int argc, char* argv[]){

    int t;
    scanf("%d", &t);
    while (t--)
    {
        scanf("%d", &n);
        init();
        for (int i = 1; i <= n; ++i)
        {
            scanf("%d%d", &arr[i].l, &arr[i].r);
            tmp[++tmpsz] = arr[i].l;
            tmp[++tmpsz] = arr[i].r;
        }
        sort(tmp + 1, tmp + tmpsz + 1);
        tmpsz = unique(tmp + 1, tmp + tmpsz + 1) - tmp - 1;
        for (int i = tmpsz; i > 1; --i) if (tmp[i] - tmp[i - 1] > 1)
            tmp[++tmpsz] = tmp[i] - 1;
        sort(tmp + 1, tmp + tmpsz + 1);
        for (int i = 1; i <= n; ++i)
        {
            arr[i].l = lower_bound(tmp + 1, tmp + tmpsz + 1, arr[i].l) - tmp;
            arr[i].r = lower_bound(tmp + 1, tmp + tmpsz + 1, arr[i].r) - tmp;
            maxs = max(maxs, arr[i].l);
            maxs = max(maxs, arr[i].r);
        }
        for (int i = 1; i <= n; ++i)
            update(arr[i].l, arr[i].r, i);
        printf("%d\n", query());
    }
    return 0;
}

//转： lioasdfghjkl.github.io