#include<bits/stdc++.h>
using namespace std;
int main(){
int a, b, c;
cin >> a >> b >> c;
if (a <= b) {
for (int i = a; i <= b; i++) {
if (i == c) {
cout << "Yes";
return 0;
}
}
} else {
for (int i = b; i <= a; i++) {
if (i == c) {
cout << "Yes";
return 0;
}
}
}
cout << "No";
return 0;
}