#include <bits/stdc++.h>
using namespace std;
int n,a[110],x;
int main(){
cin>>n;
for(int i=1;i<=n;i++){
cin>>a[i];
}
cin>>x;
int l=1,r=n;
while(l<=r){
int mid=(l+r)/2;
if(a[mid]==m){
cout<<mid;
return 0;
}else if(a[mid]<m){
l=mid+1;
}else{
r=mid-1;
}
}
cout<<"-1";
}