#include<stdio.h>
#include<string.h>
#include<ctype.h>
int main()
{
    char s[21];
    fgets(s,sizeof(s),stdin);
    s[strcspn(s,"\n")]='\0';
    for (int i=0;i<strlen(s);i++){
        if(!(isalpha(s[i]) || s[i]=='')){
            printf("Invalid Input \n");
            return 0;
            
        }
    }
    char*token=strtok(s,"");
    char*lastword=NULL;
    while(token != NULL){
        lastword=token;
        token=strtok(NULL,"");
    }
    if(lastword1=NULL){
        printf("%d\n",(int)strlen(lastword));
    }else{
        printf("0\n");
    }
    return 0;
}