#include <stdio.h>

bool v[10];

int main() {
  FILE *fin, *fout;
  fin = fopen("cfdist.in", "r");
  fout = fopen("cfdist.out", "w");

  int n, i, cfdist;
  fscanf(fin, "%d", &n);
  while (n > 0) {
    v[n % 10] = true; // marcam ca am dat de cifra
    n /= 10;
  }

  cfdist = 0;
  for (i = 0; i < 9; ++i) // parcurgem toate cifrele
    if (v[i] == true) // verificam daca am marcat cifra
      ++cfdist; // numaram

  fprintf(fout, "%d\n", cfdist);

  fclose(fin);
  fclose(fout);
  return 0;
}