Help me in solving SESO05 problem

My issue

i am error in runing this code

My code

#include <bits/stdc++.h>
using namespace std;

int main() {
    int n;
    cin>>n;
    
    int x,y;
    bool found=false;
    int a,b;
    
    for (int i=0;i<n;i++){
        
        cin>>x>>y;
        if ((x==a||y==b)&&(x==b||y==a)){
            found=true;
            
        }
    }
    cin>>a>>b;
    if(found){
        cout<<"yes"<<endl;
        
    }
    else{
        cout<<"no"<<endl;
    }

}

Learning course: Data structures & Algorithms lab
Problem Link: https://www.codechef.com/learn/course/muj-aiml-dsa-c/MUJADSAC10/problems/SESO05