/in/foo.cc: In function 'int main()':
/in/foo.cc:13:26: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   if ((num1 * b == num2) && (num1 * c == num3) || (num1 == a && num2 == b && num3 == c)) {
       ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~