Official solution
Let,
p : two numbers are not equal
q : squares of two numbers are not equal
Contrapositive of p \[ \to \] q is \[ \sim \]q \[ \to \] \[ \sim \]p.
\[ \therefore \] \[ \sim \]q \[ \to \] \[ \sim \]p means "If the squares of two numbers are equal, then the numbers are equal".