максимум на обратный

#include <iostream>
using namespace std;
int **creat(int &n, int &m)
{
	cout << "n="; cin >> n; cout << "m="; cin >> m;
	int **mas = new int*[n];
	for (int i = 0; i < n; ++i)
		mas[i] = new int[m];
	for (int i = 0; i < n; ++i)
		for (int j = 0; j < m; ++j)
		{
			cout << "mas[" << i << "][" << j << "]="; cin >> mas[i][j];
		}
	return mas;
}
int main()
{
	int n, m;
	cout << "n="; cin >> n; cout << "m="; cin >> m;
	int **a = creat(n, m);
	int max = a[0][0];
	for (int i = 0; i < n; ++i)
		for (int j = 0; j < m; ++j)
			if (a[i][j]>max)
				max = a[i][j];
	max *= -1;
		cout << "max=" << max<<endl;
	for (int i = 0; i < n; ++i)
		delete[]a[i];
	delete[]a;
	system("pause");
	return 0;
}