#include <bits/stdc++.h>
int hantei753(int n);
int main(void) {
  int i, N, answer = 0;
  scanf("%d", &N);
  for (i = 357; i <= N; i += 2) {
    answer += hantei753(i);
  }
  printf("%d", answer);
  return 0;
}
int hantei753(int n) {
  int flag3 = 0, flag5 = 0, flag7 = 0, Flag = 1, amari;
  do {
    amari = n % 10;
    if (amari == 3)
      flag3 = 1;
    else if (amari == 5)
      flag5 = 1;
    else if (amari == 7)
      flag7 = 1;
    else
      Flag = 0;
    n = n / 10;
  } while (n > 0 && Flag);
  if (Flag == 1) {
    if ((flag3 + flag5 + flag7) == 3) {
      return 1;
    }
  }
  return 0;
}
