#include<stdio.h>
int main (){
    char ch;
    int count=0;
    int hasAlpha=0;
    while((ch=getchar())!='\n'&&ch!=EOF){
        if((ch>='A'&&ch<="Z")||(ch>='a'&&ch<='z')){
            count++;
            hasAlpha=1;
            
        }
        else if(ch!=''){
            printf("just ignore");
        }
        if(hasAlpha==0){
            printf("Invaild input");
            
        }else{
            printf("%d",count);
        }
        return 0;
    }