#include <stdio.h>

int main()
{
    int n,key;
    int found=0;
    scanf("%d",&n);
    int arr[n];
    for(int i=0;i<n;i++)
    {
        scanf("%d"&arr[i]);
        scanf("%d"&key);
    }
     for(int i=0;i<n;i++)
    {
        if(arr[i]==key)
        {
            printf("Element found at index %d\n",i);
            found=1;
            break;
        }
    }
    if(!found)
    {
        printf("Element not found\n")
        
    }
    return 0;
}