#include<bits/stdc++.h> using namespace std; int main(){ int a; cin>>a; if(a>100){ cout<<"错误，请重新输入成绩"; } else if(a>=90){ cout<<"成绩为A"; } else if(a>=80){ cout<<"成绩为B"; } else if(a>=70){ cout<<"成绩为C"; } else if(a>=60){ cout<<"成绩为D"; } else if(a<60){ cout<<"成绩为E"; } }