#include<bits/stdc++.h>
using namespace std;
int main(){
	int A,B,C,D,E,x;
	scanf("%d",&x);
	if(x<10){
		cout<<A;
	}else if(x>=10&&x<20){
		cout<<B;
	}else if(x>=20&&x<40){
		cout<<C;
	}else if(x>=40&&x<50){
		cout<<D;
	}else{
		cout<<E;
	}
	
} 

/**************************************************************
	Problem: 1044
	User: zhengzihao3
	Language: C++
	Result: Wrong Answer
****************************************************************/