#include <stdio.h>
#include<string.h>
int main() {
    char s[100]={0};
    gets(s);
    int count=0;
    for(int i=0;i<strlen(s);i++){
        if((s[i]>='A'&&s[i]<='Z')||(s[i]>='a'&&s[i]<='z')||(s[i]>='0'&&s[i]<='9')){
            count++;
        }
    }
    printf("%d",count);
    return 0;
}