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