#include <bits/stdc++.h>   using namespace std;   template <class t>   inline t read(t &x) {     x = 0;     char c = getchar();     bool f = 0;     while (!isdigit(c)) f |= c ==  - , c = getchar();     while (isdigit(c)) x = (x << 1) + (x << 3) + (c ^ 48), c = getchar();     if (f) x = -x;     return x;   }   template <class t>   inline void write(t x) {     if (x < 0) {       putchar( - ), write(-x);     } else {       if (x > 9) write(x / 10);       putchar( 0  + x % 10);     }   }   const int N = 1e5 + 5;   int n, x[N], y[N], px, py;   signed main() {     read(n);     if (n & 1) {       puts( NO );       return 0;     }     for (int i = 1; i <= n; i++) read(x[i]), read(y[i]);     px = x[1] + x[n / 2 + 1];     py = y[1] + y[n / 2 + 1];     for (int i = 1, j = n / 2 + 1; j <= n; i++, j++)       if (x[i] + x[j] != px || y[i] + y[j] != py) {         puts( NO );         return 0;       }     puts( YES );   }   