1 #include<cstdio>
2 #include<cstring>
3 #include<algorithm>
4 using namespace std;
5 const int maxn=10010;
6 #define lson l,m,rt<<1
7 #define rson m+1,r,rt<<1|1
8 int a[maxn];int b[maxn];int x[maxn*3];int flag[maxn];
9 int cor[maxn<<4];
10 int cnt=0;
11 int trans(int num,int l,int r)
12 {
13 // int m=(l+r)>>1;
14 // if(num==x[m]) return m;
15 // if(num>x[m]) return trans(num,m+1,r);
16 // if(num<trans) return trans(num,l,m);
17 while(l<=r)
18 {
19 int m=(l+r)>>1;
20 if(x[m]==num) return m;
21 if(num>x[m]) l=m+1;
22 else r=m;
23 }
24 return -1;
25 }
26 void pushdown(int rt)
27 {
28 if(cor[rt]!=-1)
29 {
30 cor[rt<<1]=cor[rt];
31 cor[rt<<1|1]=cor[rt];
32 cor[rt]=-1;
33 }
34 }
35 void update(int a,int b,int i,int l,int r,int rt)
36 {
37 if(a<=l&&b>=r)
38 {
39 cor[rt]=i;
40 return;
41 }
42 pushdown(rt);
43 int m=(r+l)>>1;
44 if(a<=m) update(a,b,i,lson);
45 if(b>m) update(a,b,i,rson);
46 }
47 void query(int l,int r,int rt)
48 {
49 if(cor[rt]!=-1)
50 {
51 if(!flag[cor[rt]])
52 {
53 cnt++;
54 flag[cor[rt]]=1;
55 }
56 return;
57 }
58 if(l==r) return;
59 int m=(r+l)>>1;
60 query(lson);
61 query(rson);
62 }
63 int main()
64 {
65 int cases,n;
66 scanf("%d",&cases);
67 while(cases--)
68 {
69 scanf("%d",&n);
70 memset(cor,-1,sizeof(cor));
71 int pointer=0;
72 for(int i=0;i<n;i++)
73 {
74 scanf("%d%d",&a[i],&b[i]);
75 x[pointer++]=a[i];
76 x[pointer++]=b[i];
77 }
78 sort(x+1,x+pointer);
79 int pointer2=1;
80 for(int i=1;i<pointer;i++)
81 {
82 if(x[i]!=x[i-1]) x[pointer2++]=x[i];
83 }
84 for(int i=pointer2-1;i>=0;i--)
85 {
86 if(x[i]!=x[i-1]+1) x[pointer2++]=x[i-1]+1;
87 }
88 sort(x,x+pointer2);
89 for(int i=0;i<n;i++)
90 {
91 int l=trans(a[i],0,pointer2-1);
92 int r=trans(b[i],0,pointer2-1);
93 update(l,r,i,0,pointer2-1,1);
94 }
95 cnt=0;
96 memset(flag,0,sizeof(flag));
97 query(0,pointer2-1,1);
98 printf("%d
",cnt);
99 }
100 return 0;
101 }
