#include <bits/stdc++.h>
using namespace std;
bool J27 = 1;
template <typename Arg1>
void __f(const char* name, Arg1&& arg1) {
  if (!J27) return;
  cout << name << " : " << arg1 << '\n';
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args) {
  if (!J27) return;
  const char* comma = strchr(names + 1, ',');
  cout.write(names, comma - names) << " : " << arg1 << " | ";
  __f(comma + 1, args...);
}
inline void INP();
const long long N = 3e6 + 7;
const long long INF = LLONG_MAX;
const long long inf = INT_MAX;
long long n, Q;
long long arr[N + 2];
void solve() {
  cin >> n;
  for (long long i = 0; i < (long long)n; i++) cin >> arr[i];
  long long c1 = 0, c2 = 0;
  long long i = 0;
  while (i < n and arr[i] == arr[0]) c1++, i++;
  for (long long i = 0; i < (long long)n; i++) {
    if (i == 0 || arr[i] == arr[i - 1])
      c2++;
    else {
      if (c2 != c1) {
        cout << "No";
        return;
      }
      c2 = 1;
    }
  }
  if (c2 != c1) {
    cout << "No";
    return;
  }
  cout << "Yes";
}
int32_t main() {
  J27 = 1;
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  INP();
  long long t = 1;
  while (t--) solve();
}
inline void INP() {}
