Èç¹û´óÓÚµÈÓÚ80·Ö£¬Ð¡ÓÚµÈÓÚ100·ÖµÄͬѧÆÀ¼¶ÎªA£¬Ð¡ÓÚ80·ÖΪB.

#include<bits/stdc++.h>
using namespace std;


int main()
{
int x;
cin>>x;
if (x>=80 && x<=100)
cout<<"A";
else cout<<"b";
return 0;
}