#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ int a,b; cin>>a; a=a/10; switch(a) { case 10: case 9:cout<<"A";break; case 8: case 7:cout<<"B";break; case 6:cout<<"C";break; default:cout<<"D";break; } }