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