1 1 -1 4 3 -1 1 -12 1 -4 2 -52 -3R1 + R2 -> R2 1 1 -1 4 0 -4 4 -24 1 -4 2 -52 -R1 + R3 -> R3 1 1 -1 4 0 -4 4 -24 0 -5 3 -56 -R2/4 -> R2 1 1 -1 4 0 1 -1 6 0 -5 3 -56 5R2 + R3 -> R3 1 1 -1 4 0 1 -1 6 0 0 -2 -26 -R3/2 -> R3 1 1 -1 4 0 1 -1 6 0 0 1 13 R3 + R1 -> R1 R3 + R2 -> R2 1 1 0 17 0 1 0 19 0 0 1 13 -R2 + R1 -> R1 1 0 0 -2 0 1 0 19 0 0 1 13