#include <bits/stdc++.h> using namespace std; int main(){ int n; cin >> n; int m; int a[100]; for ( int i = 1; i <= n; i++ ){ cin >> a[i]; } cin >> m; int tnt = 0; for ( int i = 1; i <= n; i++ ){ if ( a[i] == m ){ cout << i; tnt = 1; } } if ( tnt == 0 ){ cout << "-1"; } return 0; }