#include<stdio.h>
int main(void){
    char c[20];
    int t=0;
    scanf("%s",c);
    for(int i=0;c[i]!='\0';i++){
        if((c[i]>='a'&&c[i]<='z')||(c[i]>=0&&c[i])<=9||c[i]>='A'&&c[i]<='Z')
        t++;
    }
    printf("%d",t);
    
    return 0;
}