#include <bits/stdc++.h>
using namespace std;
int l[30];
int main() {
  int n, x = 0;
  scanf("%d", &n);
  l[0] = 0;
  for (int i = 1; i <= n; ++i) scanf("%d", &l[i]);
  sort(l, l + n + 1);
  for (int i = 1; i <= n; ++i) x += l[i] - l[i - 1];
  printf("%d\n", max(x - 25, 0));
  return 0;
}
