C++ :

#include <bits/stdc++.h>
using namespace std;
int N,i,a=1;
char n[10];
int main()
{
	gets(n);
	for (int i=0;i<=strlen(n);i++)
	{
		if (n[i]>='A'&&n[i]<='Z')	N++;
		if (n[i]>='a'&&n[i]<='z')	N++;
		if (n[i]>='0'&&n[i]<='9') 	N++;
	}
	cout<<N;
	return 0;
}