func_code_string: #include <bits/stdc++.h>   using namespace std;      typedef long long big;   #define bigvec vector<big>   #define pbb pair<big, big>   #define pii pair<int, int>   #define fe first   #define se second   #define maxheap priority_queue   #define uset unordered_set   #define umap unordered_map   #define fr(i, j) for(big i = 0; i < j; i++)   #define revfr(i, j) for(big i = j - 1; i >= 0; i--)   #define speed ios_base::sync_with_stdio(false); cin.tie(NULL)   #define debug(text) if(do_debug) {cout << text << endl;}      const big mod = 1000000007;   const big infinity = 1000000000000000000;   bool do_debug = false;         void rob_santa() {       string wasted;    getline(cin, wasted);       int n_col, n_blocked;    cin >> n_col >> n_blocked;       vector<pii> blocked (n_blocked);       for(int i = 0; i < n_blocked; i++) {        cin >> blocked[i].se >> blocked[i].fe;    }       if(n_blocked == 1) {        cout <<  no  << endl;     return;    }       sort(blocked.begin(), blocked.end());          int i = 0;       for(; i < n_blocked - 1; i++) {        int x = blocked[i].fe;     int y = blocked[i].se;     //cout << x <<  ,   << y << endl;     int next_x = blocked[i + 1].fe;     int next_y = blocked[i + 1].se;        if(blocked[i].fe == blocked[i + 1].fe) {         i++;      continue;     }        if(i + 2 < n_blocked && blocked[i + 1].fe == blocked[i + 2].fe) {         cout <<  no  << endl;      return;     }           if(next_y == y) {         if(next_x - x - 1 == 0) {          i++;       continue;         } else if((next_x - x - 1) % 2 == 0){          i++;       continue;         } else {          cout <<  no  << endl;       return;      }        } else {         if((next_x - x - 1) % 2 == 1) {          i++;       continue;         } else {          cout <<  no  << endl;       return;      }     }    }       //cout << i << endl;       if(i >= n_blocked) {        cout <<  yes  << endl;       } else {        cout <<  no  << endl;    }   }         int main() {        speed;       int q;    cin >> q;       while(q-- > 0) {        rob_santa();    }       return 0;   }