#include"bits/stdc++.h"

//#include<bits/stdc++.h>
using namespace std;
#define print(x) cout<<x<<endl;
#define rep(i,a,b) for(int i=a;i<b;i++)
typedef long long ll;
const ll mod = 10000000000;

int main(){
	int h, a, d;
	double dp[10002];
	memset(dp, -1, sizeof(dp));
	cin >> h >> a >> d;
	double ans = 0;
	dp[0] = 0;
	if (h <= a || h <= d) { ans = h <= a ? 1 : 1.5; print(ans); return 0; }
	rep(i, 1, a+1)dp[i] = 1;
	rep(i, a + 1, d + 1)dp[i] = 1.5;
	rep(i, d+1, 10002) {
		dp[i] = min(dp[i - a] + 1, dp[i - d] + 1.5);
	}
	print(dp[h]);
	return 0;
}