#include <bits/stdc++.h>
int main() {
  int n, y, i, j, c, m, p;
  c = 0;
  scanf("%d", &n);
  for (i = 0; i < n; ++i) {
    scanf("%d", &y);
    if (y == 2) {
      c = c + 1;
    } else if (y < 2 || y % 2 == 0) {
    } else {
      m = sqrt(y);
      p = 0;
      for (j = 3; j <= m; j = j + 2) {
        if (y % j == 0) {
          p = 1;
          break;
        }
      }
      if (p == 0) {
        c = c + 1;
      }
    }
  }
  printf("%d/n", c);
  return 0;
}
