#include <stdio.h>
#include <string.h>
#include <ctype.h>
int main(){
    char s[100];
    int i, length, valid = 1;
    fgets(s, sizeof(s), stdin);
    s[strcspn(s, "\n")]='\0';
    for ((i = 0; s[i]) !='\0'; i++);{
        if (!isalpha(s[i]) && s[i] != ' '{
        }
            valid = 0;
            break ;
    }
}
    
    if (!valid){
        print("Invalid input");
        return 0;
    }
    length = 0;
    int n = strlen(s);
    i = n-1;
    while (i >=0 && s[i] == ' '){
        i--;
    }
    while (i >=0 && s[i] !=' '){
        length++;
        i--;
    }
    print("%d", length);
    return 0;
}