#include <iostream>
using namespace std;
int main()
{
int a;
cout<<"please input your score: "<<endl;
cin>>a;
if(a>100||a<0)
cout<<"wrong input! please try again!"<<endl;
else if(a>=90&&a<=100)
cout<<"you get an A! you are doing great job!"<<endl;
else if(a>=80&&a<90)
cout<<"you get a B! keep going!"<<endl;
else if(a>=70&&a<80)
cout<<"you get a C! It‘s OK,you can do better!"<<endl;
else if(a>=60&&a<70)
cout<<"you get an E! you pass the exam."<<endl;
else if(a<60)
cout<<"you did‘not pass the exam,but don‘t lose heart."<<endl;
return 0;
}