#include<bits/stdc++.h>
using namespace std;
int main(){
    long long n,m,a[19198100],t,i,j;
    cin>>n;
    for(i = 1;i <= n;i++){
    	cin>>m;
    	for(j = 1;j <= m;j++){
    		cin>>a[i];
    		if(a[i] == 0){
    			t++;
			}
		}
	}
	if(t == 0){
		cout<<"no"<<endl;
	}else{
		cout<<"yes"<<endl;
	}
}