#include <iostream>
int main(){
	int H,A,D;
	std::cin>>H>>A>>D;
	float ans=(H-1)/A+1;
	for(int i=0;i<H;i+=A)if(ans>(i/A)+1.5*((H-i-1)/D)+1)ans=(i/A)+1.5*((H-i-1)/D+1);
	std::cout<<ans;
}