#include<stdio.h>
#include<string.h>
#include<ctype.h>

int main(){
    char description[101];
    fgets(description,sizeof(description),stdin);
    description[strcspn(description,"\n")]=0;
    int is_numeric_only=1;
    for(int i=0;description[i];i++){
        if(!sdigit(description[i])){
            is_numeric_only=0;
            break;
        }
    }
    if(is_numeric_only){
        printf("Invalid input\n");
    }else{
        printf("%zu\n",strlen(description));
    }
    return 0;
}