杭电OJ_2004（C++版）

#include <iostream>
using namespace std;
int main(void){
	int a;
	while(cin>>a)
	{	if (a<0||a>100)
			cout<<"Score is error!"<<endl;
		else if(a>=90&&a<=100)
			cout<<"A"<<endl;
		else if(a>=80&&a<=89)
			cout<<"B"<<endl;
		else if(a>=70&&a<=79)
			cout<<"C"<<endl;
		else if(a>=60&&a<=69)
			cout<<"D"<<endl;
		else cout<<"E"<<endl;
	}
	return 0;
}