#include<iostream>
using namespace std;

int a[10];

unsigned GetDigit(unsigned num) 
{
	unsigned digit = 1;
	while (num != 0) 
	{
		a[digit] = num % 10;
		num /= 10;
		digit++;
	}
	return (digit-1);
}

int kaizyou(int n)
{
	int i, sum = 1;

	for (i = 1; i < n; i++)
	{
		sum *= 10;
	}

	return sum;
}

int main()
{
	int n, i, j, k, num, tmp, sum = 0, max = 0;

	cin >> n;

	num = GetDigit(n);

	for (i = num; i >= 1; i--)
	{
		for (j = num; j >= 1; j--)
		{
			if (i == j) break;

			tmp = a[i];
			a[i] = a[j];
			a[j] = tmp;

			for (k = num; k >= 1; k--)
			{
				sum += a[k] * kaizyou(k);
			}

			if (sum > max)
			{
				max = sum;
			}

			sum = 0;

			tmp = a[i];
			a[i] = a[j];
			a[j] = tmp;
		}
	}

	if (n > max)
	{
		cout << n << endl;
	}

	else
	{
		cout << max << endl;
	}
}