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