1 * 2 * 3 + 4
(1 + 2) + 3 + 4
(1 * 2) * 3 + 4
1 + (2 + 3) + 4
1 * (2 * 3) + 4
(1 + 2 + 3) + 4
(1 * 2 * 3) + 4
1 + (2 + 3 + 4)
1 * (2 * 3 + 4)
((1 + 2) + 3) + 4
((1 * 2) * 3) + 4
(1 + (2 + 3)) + 4
(1 * (2 * 3)) + 4
1 + ((2 + 3) + 4)
1 * ((2 * 3) + 4)
1 + (2 + (3 + 4))
(1 + 2) + (3 + 4)