#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; s[i]; i++) {
        if (!isalpha(s[i]) && s[i]  != " ") {
            printf("Invalid input\n");
            return 0;
        }
    }
    
    char *last_word = strrchr(s, " ");
    if (last_word) {
        printf("%zu\n",strlen(last_word + 1));
    } else {
        printf("%zu\n", strlen(s));
    }    
    
    return 0;
    
}