代码:
#include<bits/stdc++.h>
using namespace std;
#define MAXN 35
int main()
{
char ch;
int cnt = 0;
while(cin>>ch && ch!=EOF)
{
if(ch>='0'&&ch<='9') cnt++;
if(ch>='a'&&ch<='z') cnt++;
if(ch>='A'&&ch<='Z') cnt++;
}
cout<<cnt<<endl;
return 0;
}