in C , not C++

4. According to Euclid's algorithm for finding the greatest common divisor, gcd(m,n), of two positive integers m and n, one can take successive pairs of remainders, and when one of the remainders is zero, the other number in the pair is the ged. Letting (m,n) be the first remainder pair, we can write m = q* n + r, such that 0 sr<.>