#include <cstdio> #include <cstdlib> #include <iostream> #include <string> #include <cmath> #include <algorithm> #include <vector> #include <queue> #include <stack> #include <map> #include <set> #include <cstring> typedef long long ll; using namespace std; #define mod 1000003 #define INF 1000000000 #define LLINF 2000000000000000000LL #define SIZE 10000 int main(){ int h,a,d; int dp[SIZE*2+1],ans=INF; for(int i=0;i<=SIZE*2;i++) dp[i] = INF; dp[0] = 0; scanf("%d%d%d",&h,&a,&d); for(int i=0;i<h;i++){ dp[i+a] = min(dp[i+a],dp[i]+2); dp[i+d] = min(dp[i+d],dp[i]+3); if(i+a>=h) ans = min(ans,dp[i+a]); if(i+d>=h) ans = min(ans,dp[i+d]); } printf("%.2lf",ans/2.0); return 0; }