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