func euclid ( a, b )
begin
    if a < 0 then a := -a
    if b < 0 then b := -b
    if gcd ( a, b ) > 1 then
        print "Greatest common divisor of", a, "and", b, "is", gcd ( a, b )
    else
        print a, "and", b, "are relative primes"
    return 0
end

func gcd( a, b )
begin
    var g
    if b > 0 then
        g := gcd ( b, a - ((a/b)*b) )
    else
        g := a
    return g
end