#include <bits/stdc++.h>
using namespace std;
int main()
{
    long long k,a,b;
    cin>>k>>a>>b;
    if(k<a-3)
        cout<<k+1;
    else
        cout<<max(k+1LL,((k-a+1LL)/2LL)*(b-a)+(k-a+1LL)%2LL+a);
    return 0;
}
