program d
    implicit none
    integer(16):: K, A, B, c
    read(*,*) K, A, B

    if(A+1 >= B .or. K <= A) then
        write(*,*) K+1
    else
        c = K - A - 1
        if(mod(c,2)==0) then
            write(*,*) B + (B-A)*c/2
        else
            write(*,*) B + (B-A)*(c-1)/2+1
        end if
    end if
    stop

end program d