#include <bits/stdc++.h> using namespace std; int main() { int n, x, a[10005]; cin >> n; for (int i = 0; i < n; i++) cin >> a[i]; cin >> x; for (int i = 0; i < n; i++) if (a[i] == x) { cout << i; return 0; } cout << -1; return 0; }