#include<bits/stdc++.h> using namespace std; int a[10001]; int main(){ int n,i,k,m = -1; cin >> n; memset(a,0,sizeof(a)); for(i = 1;i <= n;i++) cin >> a[i]; cin >> k; i=0; while(i <= n && m < 0) { i++; if(a[i] == k) m = i; } cout << m << endl; return 0; }