#include<iostream>
#include<cstdio>
using namespace std;
int main()
{
int x,n,i,a[10001]={0},on=0;
scanf("%d",&n);
for ( i=1;i<=n;i++)
scanf("%d",&a[i]);
scanf("%d",&x);
i=1;
if(a[i]==x) printf("%d",i);
else
{
while(a[i]!=x&&i<=n)
{
i++;
if(a[i]==x) {on=1;printf("%d",i);}
}
}
if(on==0)
printf("%d",-1);
return 0;
}
#include<cstdio>
using namespace std;
int main()
{
int x,n,i,a[10001]={0},on=0;
scanf("%d",&n);
for ( i=1;i<=n;i++)
scanf("%d",&a[i]);
scanf("%d",&x);
i=1;
if(a[i]==x) printf("%d",i);
else
{
while(a[i]!=x&&i<=n)
{
i++;
if(a[i]==x) {on=1;printf("%d",i);}
}
}
if(on==0)
printf("%d",-1);
return 0;
}