/*

 ━━━━━┒ギリギリ♂ eye！

 ┓┏┓┏┓┃キリキリ♂ mind！

 ┛┗┛┗┛┃＼○／

 ┓┏┓┏┓┃ /

 ┛┗┛┗┛┃ノ)

 ┓┏┓┏┓┃

 ┛┗┛┗┛┃

 ┓┏┓┏┓┃

 ┛┗┛┗┛┃

 ┓┏┓┏┓┃

 ┛┗┛┗┛┃

 ┓┏┓┏┓┃

 ┃┃┃┃┃┃

 ┻┻┻┻┻┻

 */

 #include <algorithm>

 #include <iostream>

 #include <iomanip>

 #include <cstring>

 #include <climits>

 #include <complex>

 #include <fstream>

 #include <cassert>

 #include <cstdio>

 #include <bitset>

 #include <vector>

 #include <deque>

 #include <queue>

 #include <stack>

 #include <ctime>

 #include <set>

 #include <map>

 #include <cmath>

 using namespace std;

 #define fr first

 #define sc second

 #define cl clear

 #define BUG puts("here!!!")

 #define W(a) while(a--)

 #define pb(a) push_back(a)

 #define Rint(a) scanf("%d", &a)

 #define Rll(a) scanf("%I64d", &a)

 #define Rs(a) scanf("%s", a)

 #define Cin(a) cin >> a

 #define FRead() freopen("in", "r", stdin)

 #define FWrite() freopen("out", "w", stdout)

 #define Rep(i, len) for(LL i = 0; i < (len); i++)

 #define For(i, a, len) for(LL i = (a); i < (len); i++)

 #define Cls(a) memset((a), 0, sizeof(a))

 #define Clr(a, x) memset((a), (x), sizeof(a))

 #define Fuint(a) memset((a), 0x7f7f, sizeof(a))

 #define lrt rt << 1

 #define rrt rt << 1 | 1

 #define pi 3.14159265359

 #define RT return

 #define lowbit(x) x & (-x)

 #define onenum(x) __builtin_popcount(x)

 typedef long long LL;

 typedef long double LD;

 typedef unsigned long long Uint;

 typedef pair<LL, LL> pii;

 typedef pair<string, LL> psi;

 typedef map<string, LL> msi;

 typedef vector<LL> vi;

 typedef vector<LL> vl;

 typedef vector<vl> vvl;

 typedef vector<bool> vb;

 typedef struct Square {

     int x, y;

     Square() {}

     Square(int xx, int yy) : x(xx), y(yy) {}

 }Square;

 const int maxn = ;

 Square s[maxn];

 int n;

 int dp[maxn];

 bool cmp(Square a, Square b) {

     if(a.x == b.x) return a.y <= b.y;

     return a.x < b.x;

 }

 bool ok(Square a, Square b) {

     return a.x > b.x && a.y > b.y;

 }

 int main() {

     // FRead();

     int T, x, y;

     Rint(T);

     W(T) {

         Cls(dp);

         Rint(n);

         For(i, , n+) {

             Rint(x); Rint(y);

             if(x > y) swap(x, y);

             s[i] = Square(x, y);

         }

         sort(s+, s+n+, cmp);

         int ret = ;

         For(i, , n+) {

             dp[i] = ;

             For(j, , i+) {

                 if(ok(s[i], s[j])) {

                     dp[i] = max(dp[i], dp[j]+);

                 }

             }

             ret = max(dp[i], ret);

         }

         printf("%d\n", ret+);

     }

     RT ;

 }