#include <bits/stdc++.h> using namespace std; struct node { int id , num; void read() { cin >> num; } }a[10005]; bool cmp(node x , node y) { return x.num < y.num; } int main() { int n; cin >> n; for(int i = 1;i <= n;i++) { a[i].read(); a[i].id = i; } int m; cin >> m; sort(a + 1 , a + n + 1,cmp); for(int i = 1;i <= n;i++) { if(a[i].num == m) { cout << a[i].id; return 0; } } cout << -1; return 0; }