#include<cstdio>
int main(){
	int k,a,b,ans;
	scanf("%d%d%d",&k,&a,&b);
	if(b<=a+2||k<=a){
		printf("%d\n",k+1);
		return 0;
	}
	ans=a;k-=a-1;if(k&1){ans++;k--;}
	printf("%lld\n",ans+(long long)(b-a)*k/2);
	return 0;
}