1+2*3 => 7
(1+2)*3 => 9
2^10 => 1024
2^3^2 => 512
x = 7 => 7
y = x*x - 1 => 48
y / 5 => 9
y % 5 => 3
-x + 10 => 3
100 / (x - 7) => error: division by zero
(2+3 => error: missing )
7 7 => error: unexpected input
a=3 => 3
b=4 => 4
a*a + b*b => 25
