#!/usr/bin/env lua

--[[
Challenge 090

TASK #2 > Ethiopian Multiplication
Submitted by: Mohammad S Anwar
You are given two positive numbers $a and $b.

Write a script to demonstrate Ethiopian Multiplication using the given numbers.
--]]

function mul(a, b)
    local m = 0
    while (true) do
        if ((a & 1) ~= 0) then
            m = m + b
        end
        if (a <= 1) then
            break
        end
        a = a >> 1
        b = b << 1
    end
    return m
end

io.write(mul(tonumber(arg[1]), tonumber(arg[2])), "\n")