#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <climits>
#include <cfloat>
#include <map>
#include <utility>
#include <set>
#include <iostream>
#include <memory>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>
#include <sstream>
#include <complex>
#include <stack>
#include <queue>
#include <iomanip>
using namespace std;
#define INF 1e9
#define PI acos(-1)
typedef long long ll;


int main() {
	int n; cin >> n;
	int pos = 1, sum = n, ans=n;
	map<int, int> num;
	while (n != 0) {
		num[pos] = n%10;
		n /= 10; pos++;
	}

	for (int i = 1; i < pos-1; i++) {
		for (int j = i + 1; j < pos; j++) {
			ans = max(ans, sum - num[i] * (int)pow(10 , (i - 1)) - num[j] * (int)pow(10, (j - 1))
				+ num[i] * (int)pow(10, (j - 1)) + num[j] * (int)pow(10, (i - 1)));
		}
	}

	cout << ans << endl;

	return 0;
}