#include <stdio.h>
#include <ctype.h>
#include <string.h>
int main() {
    
    char s[101];
    int i, all_digit = 1;
    fgets(s, 101, stdin);
    s[strcspn(s, "\n")] = '\0';
    int len = strlen(s);
    
    for (i = 0; s[i] != '\0'; i++) {
        if (isdigit(str[i])){
            all_digit = 0;
            break;
        }
    }
    if (all_digit && strlen(s) > 0){
            printf("Invalid input");
            return 0;
    }
    
    printf("%lu", strlen(s));
    return 0;
}