#include<bits/stdc++.h>
using namespace std;
int main()
{
	long long x,y;
	char c;
	cin>>x>>c;
	if(x<=1000)
	{
		if(c=='n')
		{
			cout<<"8";
		}
		else
		{
			cout<<"13";
		}
	}
	if(x>1000)
	{
		if((x-1000)%500!=0)
		{
			if(c=='n')
			{
				cout<<((x-1000)/x+1)*4+8;
			}
			else
			{
				cout<<((x-1000)/x+1)*4+13;
			}
		}
	}
}