There are three rectangular tanks. The first tank has length, breadth and height each equal to \(m\) meters, the second tank has length, breadth and height each equal to \(n\) meters, and the third tank has length, breadth and height equal to \(m\) meters, \(n\) meters and \(1\) meter respectively. It is known that \(m\) and \(n\) are integers. Initially, the first tank is full of water. Then the second and third tanks are completely filled using the water from the first tank. After this, the first tank still has 85{,000 liters of water. If \(1 \text{ m}^3 = 1000\) liters, find the value of \(m\).}