#include <bits/stdc++.h>
using namespace std;
int x;
double sum=0;
char a,b;
int main(){
	cin>>x;
	cin>>a>>b;
	if(a=='B'){
		if(b=='C'){
			sum=x*0.6;
		}else{
			sum=x*0.8;
		}
		cout<<sum;
	}
	if(a=='A'){
		if(b=='A'){
			sum=x;
		}else if(b=='B'){
			sum=x*0.8;
		}else if(b=='C'){
			sum=x*0.7;
		}
		cout<<sum;
	}
	if(a=='C'){
		if(b=='A'){
			sum=x*0.7;
		}else if(b=='B'){
			sum=x*0.6;
		}else if(b=='C'){
			sum=x*0.7;
		}
		cout<<sum;
	}
    return 0;
}