#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long
#define INF 0x3f3f3f3f
#define PII pair<ll, ll>
const ll mod = 1e9 + 7;
const ll MAXN = 500005;
const ll base1 = 131;
const ll base2 = 127;
ll _ = 1, n, m, ans = 0, a[MAXN], f[MAXN];
void solve()
{
	string s;
	cin >> s;
	ll s1 = s[0] - '0';
	ll s2 = s[2] - '0';
	if (s1 >= s2)
	{
		cout << s1 << '-' << s2 << '\n';
	}
	else
	{
		cout << s2 << '-' << s1 << '\n';
	}
}
signed main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	// cin>>_;
	while (_--)
	{
		solve();
	}
	return 0;
}