#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
typedef long long ll;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define repr(i, n) for (int i = (int)(n) - 1; i >= 0; i--)
#define repk(i, k, n) for (int i = k; i < (int)(n); i++)
#define all(v) v.begin(), v.end()
#define mod1 1000000007
#define mod2 998244353
#define vi vector<int>
#define vs vector<string>
#define vc vector<char>
#define vl vector<ll>
#define vvi vector<vector<int>>
#define vvc vector<vector<char>>
#define vvl vector<vector<ll>>
#define vvvi vector<vector<vector<int>>>
#define vvvl vector<vector<vector<ll>>>
#define pii pair<int,int>
#define pil pair<int,ll>
#define pli pair<ll, int>
#define pll pair<ll, ll>
#define vpii vector<pair<int,int>>
#define vpll vector<pair<ll,ll>>
#define vvpii vector<vector<pair<int,int>>>
#define vvpll vector<vector<pair<ll,ll>>>

template<typename T> void debug(T e){
    cerr << e << endl;
}

template<typename T> void debug(vector<T> &v){
    rep(i, v.size()){
        cerr << v[i] << " ";
    }
    cerr << endl;
}

template<typename T> void debug(vector<vector<T>> &v){
    rep(i, v.size()){
        rep(j, v[i].size()){
            cerr << v[i][j] << " ";
        }
        cerr << endl;
    }
}

template<typename T> void debug(vector<pair<T, T>> &v){
    rep(i,v.size()){
        cerr << v[i].first << " " << v[i].second << endl;
    }
}

template<typename T> void debug(set<T> &st){
    for (auto itr = st.begin(); itr != st.end(); itr++){
        cerr << *itr << " ";
    }
    cerr << endl;
}

template<typename T> void debug(multiset<T> &ms){
    for (auto itr = ms.begin(); itr != ms.end(); itr++){
        cerr << *itr << " ";
    }
    cerr << endl;
}

template<typename T> void debug(map<T, T> &mp){
    for (auto itr = mp.begin(); itr != mp.end(); itr++){
        cerr << itr->first << " " << itr->second << endl;
    }
}

void debug_out(){
    cerr << endl;
}

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T){
    cerr << H << " ";
    debug_out(T...);
}



int main(){
    ll N,M;
    cin >> N >> M;
    vl H(N);
    rep(i,N) cin >> H[i];
    vl X(M);
    vl Y(M);
    rep(i,M){
        cin >> X[i] >> Y[i];
        X[i]--;
        Y[i]--;
    }
    vvl graph(N, vl(0));
    for (ll i = 0; i < M; i++){
        graph[X[i]].push_back(Y[i]);
        graph[Y[i]].push_back(X[i]);
    }
    ll INF = 1000000000000000;

    vl dp1(N, -INF);
    vl dp2(N, -INF);
    dp1[0] = 0;
    for (ll i = 0; i < N; i++){
        for (auto x: graph[i]){
            if (x <= i){
                continue;
            }
            if (H[x] > H[i]){
                dp2[x] = max(dp2[x], dp1[i] + abs(H[x] - H[i]));
            }
            else{
                dp1[x] = max(dp1[x], dp1[i]);
                dp1[x] = max(dp1[x], dp2[i]);
            }
        }
    }
    //debug(dp1);
    //debug(dp2);
    if (max(dp1[N - 1], dp2[N - 1]) < 0) cout << -1 << endl;
    else cout << max(dp1[N - 1], dp2[N - 1]) << endl;

    vl dp3(N, -INF);
    vl dp4(N, -INF);
    dp3[N - 1] = 0;
    for (ll i = N - 1; i >= 0; i--){
        for (auto x: graph[i]){
            if (x >= i){
                continue;
            }
            if (H[x] > H[i]){
                dp4[x] = max(dp4[x], dp3[i] + abs(H[x] - H[i]));
            }
            else{
                dp3[x] = max(dp3[x], dp3[i]);
                dp3[x] = max(dp3[x], dp4[i]);
            }
        }
    }
    if (max(dp3[0], dp4[0]) < 0) cout << -1 << endl;
    else cout << max(dp3[0], dp4[0]) << endl;
}