#include <iostream>
#define REP(i, a, n) for(ll i = ((ll) a); i < ((ll) n); i++)
#define INF 1000000000LL
#define fi first
#define se second
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;

ll N, C, V;
pll dp[100001];

int main(void) {
  cin >> N >> C >> V;

  REP(i, 0, N + 1) dp[i] = pll(-INF, -INF);
  dp[0] = pll(1, 0);

  ll ans;
  REP(i, 0, 100001) {
    if(dp[i].fi >= N) {
      ans = i;
      break;
    }
    ll c = i + C;
    ll v = i + V;
    if(c >= 100000) c = 100000;
    if(v >= 100000) v = 100000;
    dp[c] = max(dp[c], pll(dp[i].fi, dp[i].fi));
    dp[v] = max(dp[v], pll(dp[i].fi + dp[i].se, dp[i].se));
  }
  cout << ans << endl;
}