#include #include #include #include #include #include #define LL __int64 using namespace std; LL sum[100010],a[100100]; map q; int main () { int t; scanf("%d",&t); while(t--){ q.clear(); int n,m; scanf("%d %d",&n,&m); scanf("%d",&a[0]); sum[0] = a[0]; q[sum[0]]++; bool flag = false; for(int i=1;i0){ flag = true; break; } } if(flag) break; } if(flag) printf("YES\n"); else printf("NO\n"); } return 0; }