#include<bits/stdc++.h>
using namespace std;
int main(){
	float n,m,x;
	cin>>n>>m;
	if(1<=m&&m<2){
		x=n*1.0325;
		printf("%.1f",x);
	}else if(2<=m&&m<3){
		x=n*1.0375;
		printf("%.1f",x);
	}else if(3<=m&&m<5){
		x=n*1.0425;
		printf("%.1f",x);
	}else{
		x=n*1.0475+190;
		printf("%.1f",x);
	}
	
}

/**************************************************************
	Problem: 1341
	User: zhengzihao3
	Language: C++
	Result: Wrong Answer
****************************************************************/