#include <bits/stdc++.h>
using namespace std;
int main () {
	char a[10];
	gets(a);
	int ana = 0;
	int n=strlen(a);
	for (int i = 0; i <n; i++) {
		if (a[i] >= 'A' && a[i] <= 'Z')
			ana++;
		if (a[i] >= 'a' && a[i] <= 'z')
			ana++;
		if (a[i] >= '0' && a[i] <= '9')
			ana++;
	}
	cout << ana;
}