# include<iostream> using namespace std; int main(){ int a,b; char op; cin>>a; b=a/10; switch(b){ case 9: case 10: cout<<"A"; break; case 8: case 7: cout<<"B"; break; case 6: cout<<"C"; break; case 5: case 4: case 3: case 2: case 1: case 0: cout<<"D"; break; } return 0; }