Help me in solving P2P problem

help
,
1

My issue

explain this problem

My code

#include <bits/stdc++.h>
using namespace std;
void sol(){
    int t;
    cin>>t;
    while(t--){
        int n;
        cin>>n;
        string A,B;
        cin>>A>>B;
        int o=0;
        for(int i=0;i<n;i++){
            if(A[i]=='1') o++;
            if(B[i]=='1') o++;
        }
        
        if(o%2==1){
            cout<<"YES"<<endl;
        }else{
            cout<<"NO"<<endl;
        }
    }
}

int main() {
	ios_base:: sync_with_stdio(false);
	cin.tie(nullptr);
	sol();
	return 0;

}

Problem Link: Make Odd Practice Coding Problem