#include <iostream>
using namespace std;
int main()
{
    string s;
    cin >> s;
    int sum = 0;
    for(int i =0;i < s.length();i++)
	{
        if(s[i] >= 'a' && s[i] <= 'z')
		{
			sum++;
		}
		if(s[i] >= 'A' && s[i] <= 'Z')
		{
			sum++;
		}
		if(s[i] >= '0' && s[i] <= '9')
		{
   			sum++;
		}
    }
    cout << sum;
	return 0;
}