#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef long double ld;
typedef vector<ll> vl;
typedef vector<string> vs;
typedef vector<char> vc;
typedef queue<ll> ql;
typedef deque<ll> dql;
typedef priority_queue<ll, vl/*, greater<ll>*/> pql; //降順(/*昇順*/)
typedef set<ll> sl;
typedef pair<ll, ll> pl;
typedef vector<vl> vvl;
typedef vector<pl> vpl;
#define rep(i, n) for(ll i = 0; i < ll(n); ++i)
#define rep2(i, n) for(ll i = 1; i <= ll(n); ++i)
//#define rep(i, k, n) for(ll i = k-1; i < ll(n); ++i)
//#define rep2(i, k, n) for(ll i = k; i <= ll(n); ++i)
#define all(v) (v).begin(), (v).end()
bool chmin(ll &a, ll b) {if(b < a) {a = b; return 1;} return 0;}
bool chmax(ll &a, ll b) {if(b > a) {a = b; return 1;} return 0;}
const ll INF = 1LL << 60;
const ll MOD = 1e9 + 7;
//const ll MOD = 998244353;
const ll MAX = 1e9;
const char newl = '\n';

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);

  ll a, b, c;
  cin >> a >> b >> c;
  
  cout << ((a-c)*(c-b)>=0 ? "Yes" : "No") << newl;
  return 0;
}

#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(n);++i)
#define all(a) (a).begin(),(a).end()
#define dunk(a) cout << (a) << endl
using namespace std;
typedef long long ll;

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	int a, b, c;
	cin >> a >> b >> c;

	if ((a < c && b > c) || (a > c&& b < c)) puts("Yes");
	else puts("No");

	return 0;
}