text: #pragma once
  #include <sstream>
  #include <stdexcept>
  #include <iostream>
  #include <map>
  #include <set>
  #include <string>
  #include <vector>
  
  
  using namespace std;
  template <class T>
  ostream& operator << (ostream& os, const vector<T>& s) {
    os << "{";
    bool first = true;
    for (const auto& x : s) {
      if (!first) {
        os << ", ";
      }
      first = false;
      os << x;
    }
    return os << "}";
  }
  
  ыtemplate <class T>
  ostream& operator << (ostream& os, const set<T>& s) {
    os << "{";
    bool first = true;
    for (const auto& x : s) {
      if (!first) {
        os << ", ";
      }
      first = false;
      os << x;
    }
    return os << "}";
  }
  
  template <class K, class V>
  ostream& operator << (ostream& os, const map<K, V>& m) {
    os << "{";
    bool first = true;
    for (const auto& kv : m) {
      if (!first) {
        os << ", ";
      }
      first = false;
      os << kv.first << ": " << kv.second;
    }
    return os << "}";
  }
  
  template<class T, class U>
  void AssertEqual(const T& t, const U& u, const string& hint = {}) {
    if (!(t == u)) {
      ostringstream os;
      os << "Assertion failed: " << t << " != " << u;
      if (!hint.empty()) {
         os << " hint: " << hint;
      }
      throw runtime_error(os.str());
    }
  }
  
  inline void Assert(bool b, const string& hint) {
    AssertEqual(b, true, hint);
  }
  
  class TestRunner {
  public:
    template <class TestFunc>
    void RunTest(TestFunc func, const string& test_name) {
      try {
        func();
        cerr << test_name << " OK" << endl;
      } catch (exception& e) {
        ++fail_count;
        cerr << test_name << " fail: " << e.what() << endl;
      } catch (...) {
        ++fail_count;
        cerr << "Unknown exception caught" << endl;
      }
    }
  
    ~TestRunner() {
      if (fail_count > 0) {
        cerr << fail_count << " unit tests failed. Terminate" << endl;
        exit(1);
      }
    }
  
  private:
    int fail_count = 0;
  };
  
  #define ASSERT_EQUAL(x, y) {            \
    ostringstream os;                     \
    os << #x << " != " << #y << ", "      \
      << __FILE__ << ":" << __LINE__;     \
    AssertEqual(x, y, os.str());          \
  }
  
  #define ASSERT(x) {                     \
    ostringstream os;                     \
    os << #x << " is false, "             \
      << __FILE__ << ":" << __LINE__;     \
    Assert(x, os.str());                  \
  }
  
  #define RUN_TEST(tr, func) \
    tr.RunTest(func, #func)
  