题解

#include<bits/stdc++.h>
using namespace std;
string s;
int sum;
int main(){
getline(cin,s);
for(int i=0;i<s.size();i++){
if(('0'<=s[i]&&s[i]<='9')||('a'<=s[i]&&s[i]<='z')||('A'<=s[i]&&s[i]<='Z'))
{
sum++;
}
}
cout<<sum;
}