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

int main(){
    char title[1001];
    char ptr;
    int count;
    int i;
    int is_valid = 1;
    
    if(fgets(title, sizeof(title),stdin) == NULL){
        return 0;
    }
    
    size_t len = strlen(title);
    if(len>0 &&title[len-1] == '\n'){
        title[len-1] = '\0';
    }
    
    for(i =0; *(ptr + i)!='\0'; i++){
        char curr = *(ptr+i);
        if(isalpha(curr)){
            count++;
        }else if(curr != ' '){
            is_valid = 0;
            break;
        }
    }
    
    if(is_valid){
        printf("%d\n",count);
    }else{
        prinf("Invalid input")
    }
    return 0;
}