k,a,b=io.read("*n","*n","*n")

if b-a<=2 then
    print(k+1)
else
    if k-(a-1)>=2 then
        x=(k-(a-1))//2
        y=(k-(a-1))%2
        print(a+(b-a)*x+y)
    else
        print(k+1)
    end
end