#include using namespace std; #define int long long int #define all(a) a.begin(), a.end() #define rall(a) a.rbegin(), a.rend() #define sz(a) (int)a.size() #define V vector #define ff first #define ss second #define rep(i, a, n) for (int i = a; i < n; i++) #define rev(i, a, n) for(int i = a; i > n; i--) #define out(a) cout << a << "\n" #define outv(a) rep(i, 0, (int)a.size()) cout << a[i] << " "; cout << endl; #define in(a) for(auto &i: a) cin >> i; #define pb push_back #define pii pair const int mod1 = 1e9+7, mod2 = 998244353; void solve(){ int n; cin >> n; V a(n); in(a); for(int i = 1; i + 1 < n; i++) { if(a[i] + a[n - i - 1] != a[0] + a[n - 1]) { cout << "No\n"; return; } } cout << "Yes\n"; } signed main(){ ios_base::sync_with_stdio(NULL); cin.tie(NULL); int t = 1; // cin >> t; while(t--){ solve(); } }