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

int main()
{
    char str[101];
    int i, len, lastLen = 0;
    
    fgets(str, sizeof(str), stdin);
    str[strcspn(str , "\n")] = '\0';
    len = strlen(str);
    
    for (i=0;i<len;i++)
    {
        if(str[i] == '\'' || str[i] == ' " ') continue;
        if(!isalpha(str[i]) && str[i] != ' ')
        {
            printf("Invalid input");
            return 0;
        }
    }
    i = len -1;
    
    while (i>= 0 && str[i] == ' ' || str[i] == '\'' || str[i] == ' " ') i--;
    
    while(i >= 0 && str[i] != ' ' && str[i] != '\'' && str[i] !=' " '){
        lastLen++;
        i--;
    }
    printf("%d", lastLen);
    
    return 0;
    
}