#include<bits/stdc++.h>
#define forr(i, a, b) for(int i = (a); i < (b); i++)
#define rep(i,n) for(int i = 0; i < (n); i++)
#define rrep(i,n) for(int i = 1; i <= (n); i++)
#define ALL(a) (a.begin()),(a.end())
using namespace std;
typedef long long ll;
typedef pair<int,int> P;
typedef pair<ll, ll> LP;
const ll LINF = 1LL<<60;
const int INF = 1001001001;

/* --------------------------------------------------- */

int main() {
    int a, b, c;
    cin >> a >> b >> c;
    if(a < c && c < b || a > c && c > b) cout << "Yes" << endl;
    else cout << "No" << endl;

    return 0;
}
#include <bits/stdc++.h>
using namespace std;
#define _GLIBCXX_DEBUG
#define rep(i, from, to) for (int i = from; i < (to); ++i)
#define mp(x,y) make_pair(x,y)
#define all(x) (x).begin(),(x).end()
#define pb push_back
using ll = long long;
using vin=vector<int>;
using vll=vector<ll>;
using vst=vector<string>;
using P = pair<int, int>;
const int inf=1e9+7;
const ll INF=1e18;
template <typename T> void chmin(T &a, T b) { a = min(a, b); }
template <typename T> void chmax(T &a, T b) { a = max(a, b); }
template<class T> inline void Yes(T condition){ if(condition) cout << "Yes" << endl; else cout << "No" << endl; }
template<class T> inline void YES(T condition){ if(condition) cout << "YES" << endl; else cout << "NO" << endl; }
const int dx[4] = { 1, 0, -1, 0 };
const int dy[4] = { 0, 1, 0, -1 };


int main(){cout<<fixed<<setprecision(10);
		   int a,b,c;
           cin>>a>>b>>c;
           Yes((a-c)*(b-c)<0);
}