2_A

#include <iostream>
#include <stack>
#include <string>

using std::cin;
using std::cout;
using std::stack;
using std::string;

int main() {
  stack<int> bank;
  string str;
  cin >> str;
  int len = str.size();
  int bal = 0;
  bool ok = true;
  for (int i = 0; i < len; ++i) {
    char lt = str[i];
    char pre = '*';
    if (!bank.empty()) {
      pre = bank.top();
    }
    if (lt == ')') {
      bal--;
      if (pre == '(') {
        bank.pop();
      } else {
        ok = false;
        break;
      }
    } else if (lt == ']') {
      bal--;
      if (pre == '[') {
        bank.pop();
      } else {
        ok = false;
        break;
      }
    } else if (lt == '}') {
      bal--;
      if (pre == '{') {
        bank.pop();
      } else {
        ok = false;
        break;
      }
    } else {
      bal++;
      bank.push(lt);
    }
  }
  if (bal != 0) {
    ok = false;
  }
  if (ok) {
    cout << "YES\n";
  } else {
    cout << "NO\n";
  }
}