#include<bits/stdc++.h>

using namespace std;

using int64 = long long;

const int mod = 998244353;

const int64 infll = (1LL << 62) - 1;

const int inf = (1 << 30) - 1;

struct IoSetup {
  IoSetup() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
    cerr << fixed << setprecision(10);
  }
} iosetup;

template< typename T1, typename T2 >
ostream &operator<<(ostream &os, const pair< T1, T2 > &p) {
  os << p.first << " " << p.second;
  return os;
}

template< typename T1, typename T2 >
istream &operator>>(istream &is, pair< T1, T2 > &p) {
  is >> p.first >> p.second;
  return is;
}

template< typename T >
ostream &operator<<(ostream &os, const vector< T > &v) {
  for (int i = 0; i < (int) v.size(); i++) {
    os << v[i] << (i + 1 != v.size() ? " " : "");
  }
  return os;
}

template< typename T >
istream &operator>>(istream &is, vector< T > &v) {
  for (T &in: v) is >> in;
  return is;
}

template< typename T1, typename T2 >
inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }

template< typename T1, typename T2 >
inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }

template< typename T = int64 >
vector< T > make_v(size_t a) {
  return vector< T >(a);
}

template< typename T, typename... Ts >
auto make_v(size_t a, Ts... ts) {
  return vector< decltype(make_v< T >(ts...)) >(a, make_v< T >(ts...));
}

template< typename T, typename V >
typename enable_if< is_class< T >::value == 0 >::type fill_v(T &t, const V &v) {
  t = v;
}

template< typename T, typename V >
typename enable_if< is_class< T >::value != 0 >::type fill_v(T &t, const V &v) {
  for (auto &e: t) fill_v(e, v);
}

template< typename F >
struct FixPoint: F {
  explicit FixPoint(F &&f): F(forward< F >(f)) {}

  template< typename... Args >
  decltype(auto) operator()(Args &&... args) const {
    return F::operator()(*this, forward< Args >(args)...);
  }
};

template< typename F >
inline decltype(auto) MFP(F &&f) {
  return FixPoint< F >{forward< F >(f)};
}

int main() {
  int N, M;
  cin >> N >> M;
  vector< int > H(N);
  cin >> H;
  vector< vector< int > > g(N);
  for(int i = 0; i < M; i++) {
    int a, b;
    cin >> a >> b;
    --a, --b;
    g[a].emplace_back(b);
    g[b].emplace_back(a);
  }
  {
    auto dp = make_v< int64 >(N, 2);
    fill_v(dp, -infll);
    dp[0][0] = 0;
    for(int i = 0; i < N; i++) {
      for(auto& j : g[i]) {
        if(i < j) {
          if(H[i] < H[j]) chmax(dp[j][1], dp[i][0] + H[j] - H[i]);
          else chmax(dp[j][0], max(dp[i][1], dp[i][0]));
        }
      }
    }
    cout << max({dp[N - 1][0], dp[N - 1][1], -1LL}) << endl;
  }
  {
    auto dp = make_v< int64 >(N, 2);
    fill_v(dp, -infll);
    dp[N - 1][0] = 0;
    for(int i = N - 1; i >= 0; i--) {
      for(auto& j : g[i]) {
        if(i > j) {
          if(H[i] < H[j]) chmax(dp[j][1], dp[i][0] + H[j] - H[i]);
          else chmax(dp[j][0], max(dp[i][1], dp[i][0]));
        }
      }
    }
    cout << max({dp[0][0], dp[0][1], -1LL}) << endl;
  }
}