#include <iostream>
using namespace std;
int main(){
  long long k,a,b;cin>>k>>a>>b;
  if(!(a < b-1))cout << k+1 << endl;
  else cout << (long long)(k-(a-1))/2*b + (k-(a-1))%2 - ((k-(a-1))/2-1)*a << endl;
}