#include<bits/stdc++.h>
using namespace std;
char s[10];
int main()
{
	int ans = 0;
	cin >> s;
		for (int i = 0; i <strlen(s); i++) {
			if (s[i] >= 'A' && s[i] <= 'Z')
				ans++;
			if (s[i] >= 'a' && s[i] <= 'z')
				ans++;
			if (s[i] >= '0' && s[i] <= '9')
				ans++;
	}
	printf("%d", ans);
	return 0;
}