#include<iostream> #include<algorithm> using namespace std; int a[10001]; int main(){ int n,m; cin>>n; for(int i=1;i<=n;i++){ cin>>a[i]; } cin>>m; for(int i=1;i<=n;i++){ if(a[i]==m){ cout<<i<<endl; exit(0); } } cout<<-1<<endl; return 0; }