#include #include #include #include using namespace std; #define REP(i,s,e) for (i = s; i <= e; i++) #define rep(i,n) REP (i,0,(int)(n)-1) #define RREP(i,s,e) for (i = s; i >= e; i--) #define rrep(i,n) RREP (i,(int)(n)-1,0) #define INF (int)1e8 #define MOD (int)(1e9+7) typedef long long ll; int main(void) { int i, h, a, d; double ans = 1e5; cin >> h >> a >> d; rep (i,(h+a-1)/a+1) ans = min(ans,i+(max(0,h-a*i)+d-1)/d*1.5); cout << ans << endl; return 0; }