#include <stdio.h>
#include<string.h>
int main()
{char s[10];
scanf("%s",&s);
int j=0;
int n=strlen(s);
for(int i=0;i<n;i++){
if('a'<=s[i]&&s[i]<='z')
j++;
if('A'<=s[i]&&s[i]<='Z')
j++;
if('0'<=s[i]&&s[i]<='9')
j++;}
printf("%d",j);
return 0;}