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