#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
  ll k,a,b,ans=1;
  cin >> k >> a >> b;
  if(b-a<=2){
    cout << k+1 << endl;
    return 0;
  }
  ans+=a-1;
  k-=a-1;
  ans+=k%2;
  k-=k%2;
  ans+=(b-a)*k/2;
  cout << ans << endl;
}