#include <stdio.h>
#include <string.h>
#include <ctype.h>
int main(){
    char s[100];
    int i,n, length= 0;
    fgets(s, sizeof(s); stdin);
    n=strlen(s);
    if(s[n-1]=='\n'){
        s[n-1]='\0';
        n--;
    }
for (i=0; i<n; i++){
    if(!(isalpha(s[i] || isspace(s[i]))) {
        printf("Invalid input\n");
        return 0;
    }
}
while(i>=0 && s[i]==' ')
i--;
while(i>=0 && isalpha(s[i])){
    length++;
    i--;
}
printf("%d\n",length);
return 0;
}