CF632A Grandma Laura and Apples

#include<bits/stdc++.h>
using namespace std;
long long n,p,ans=0,total=0,apple=0;
int main()
{
	string a[100000];
	cin>>n>>p;
	p=p>>1;
	for(int i=1;i<=n;i++)
	{
	cin>>a[i];
}
for(int i=n;i>=1;i--)
{
	total=total*2;
	if(a[i]=="halfplus")
		total++;
	apple+=total;
	}
	cout<<apple*p;
	return 0;
}