#include < vector >
using namespace std;
signed main()
{
constexp int key = 5;
vector < int > A(n);
int n;
cin >> n;
for (int i = 0; i < n; i++)
cin >> A[i];
if (A[i] == key)
cout << i << endl;
}
return 0;
#include < vector >
using namespace std;
signed main()
{
constexp int key = 5;
vector < int > A(n);
int n;
cin >> n;
for (int i = 0; i < n; i++)
{
cin >> A[i];
if (A[i] == key)
cout << i << endl;
}
return 0;
}