#include<stdio.h>
#include<string.h>
#include<ctype.h>
int man(){
    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(lastword!=NULL){
    printf("%d\n",(int)strlen(lastword));
}
else{
    printf("0\n");
}
return 0;
}