#include <iostream>
using namespace std;
int main()
{
int n, v[100], OK=1;
cin >> n;
for (int i = 0; i < n; i++) cin >> v[i];
for (int i = 0; i < n-1; i++)
{
if (v[i] != v[i + 1]) OK = 0;
}
if (OK) cout << "Este constant.";
else cout << "Nu este constant.";
return 0;
}