[http://www.codechef.com/problems/RRMATRIX][1] I read the editorial. Every element is in form of Ai, j = i * M + j + 1 Bi, j = j * N + i + 1 equating the two, we get i * M + j + 1 = j * N + i + 1 ⇒ i * (M-1) = j * (N-1) ⇒ i / j = (N-1) / (M-1) = p / q up to now every thing is clear,but i cant understand the next steps,and i thing(i,j) gives the postions of similar elements in both matrices,but what is (l*p,l*q) cant understand any one please help.