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

int main() {
    char s[1000];
    int i, count = 0, digitOnly = 1;
    fgets(s, sizeof(s), stdin);
    
    for (i = 0; s[i] && s[i] != '\n'; i++) {
        if (isalpha(s[i])) count++;
        if (!isspace(s[i]) && !isdigit(s[i]))
    digitonly = 0;
    if (isalpha(s[i])) digitonly = 0;
    }
  int onlyDigits = 1;
for (i = 0; s[i] && != '\n'; i++)
    if (!isdigit(s[i])) && !isspace(s[i]))
omlyDigits = 0;
    if (onlyDigits)
       printf("Invalid input");
    else
       printf("%d" , count);
    return 0;  
}