#include<stdio.h>
#include<string.h>
#include<ctype.h>
int main()
{
    char s[21];
    fgets(s, sizeof(s), stdin);
    int len = strlen(s);
    if (s[len -1] == '\n') s[--len]='\0';
    for (int i=0; i<len; i++){
        if (!isalpha(s[i]) && s[i] != ' ')
        {
            printf("Invalid input\n");
            return 0;
        }
    }
    int i = len-1, count = 0;
    while (i >= 0 && s[i] == ' ')i--;
     while (i >= 0 && s[i] !== ' ')i--;{
     count++; }
     printf("%d\n", count);
     return 0;
    
}