#include <stdio.h>

int main () {
  int n = 0;
  char s[200001] = "";
  
  int res = 0;
  
  int ans = 0;
  int cnt[10] = {};
  int flg[40] = {};
  
  res = scanf("%d", &n);
  res = scanf("%s", s);
  
  for (int i = 0; i < n; i++) {
    cnt[(int)(s[i]-'0')]++;
  }
  
  if (n < 2) {
    printf("1\n");
    return 0;
  }
  
  if (n < 3 && s[0] == s[1]) {
    printf("1\n");
    return 0;
  }
  
  if (n < 3) {
    printf("2\n");
    return 0;
  }
  
  for (int i = 0; i < 1000; i++) {
    int tmpcnt[10] = {};
    int tmp = i;
    int is_ok = 1;
    tmpcnt[i%10]++;
    tmpcnt[(i/10)%10]++;
    tmpcnt[i/100]++;
    for (int j = 0; j < 10; j++) {
      if (tmpcnt[j] > cnt[j]) {
        is_ok = 0;
      }
    }
    if (is_ok > 0) {
      flg[i%40] = 1;
    }
  }
  
  for (int i = 0; i < 40; i++) {
    ans += flg[i];
  }
  
  printf("%d\n", ans);
  return 0;
}