# (1 /\ 2) + 3 = 4
1/\2+3
# (3 + 1) /\ 2 = 2
3+1/\2
# 1 + (2 * 3) = 7
1+2*3
# (3 * 2) + 1 = 7
3*2+1
# (-2) + 3 = 1
-2+3
# 2 + ( -3) = -1
2+-3
# (((1 - 2) + 3) - 4) + 5 = 3
1-2+3-4+5
# (((-1 + 2) - 3) + 4) - 5 = -3
-1+2-3+4-5