#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a[n + 1];
  a[0] = 0;
  for (int i = 1; i < n + 1; i++) {
    cin >> a[i];
  }
  int ans = a[n] + 15;
  for (int i = 0; i < n; i++) {
    if (a[i + 1] - a[i] <= 15)
      continue;
    else {
      ans = a[i] + 15;
      break;
    }
  }
  if (ans > 90) ans = 90;
  cout << ans << "\n";
}
