#include<iostream>

using namespace std;

int main(){
    long long k,a,b;
    cin >> k >> a >> b;
    long long r = k-a+1;
    if((b-a)/2<1){
        cout << a+r << endl;
    }else{
        cout << (b-a)*(r/2) + r%2 + a << endl;
    }
    return 0;
}