#include "bits/stdc++.h"
using namespace std;
void abc() {cout << endl;}
template <typename T, typename ...U> void abc(T a, U ...b) {
cout << a << ' ', abc(b...);
}
template <typename T> void printv(T l, T r) {
while (l != r) cout << *l << " \n"[++l == r];
}
template <typename A, typename B> istream& operator >> (istream& o, pair<A, B> &a) {
return o >> a.first >> a.second;
}
template <typename A, typename B> ostream& operator << (ostream& o, pair<A, B> a) {
return o << '(' << a.first << ", " << a.second << ')';
}
template <typename T> ostream& operator << (ostream& o, vector<T> a) {
bool is = false;
for (T i : a) {o << (is ? ' ' : '{'), is = true, o << i;}
return o << '}';
}
#ifdef local
#define test(args...) abc("[" + string(#args) + "]", args)
#else
#define test(args...) void(0)
#endif
using ll = long long;
ll v[100005];
int deg[100005];
vector<pair<int, int>> adj[100005];
ll calc[500005];
bool seen[100005];
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
// freopen("", "r", stdin);
// freopen("", "w", stdout);
int n, m; cin >> n >> m;
for (int i = 1; i <= n; i++) cin >> v[i];
for (int i = 1; i <= m; i++) {
int a, b; cin >> a >> b;
adj[a].push_back({b, i});
adj[b].push_back({a, i});
deg[a]++; deg[b]++;
}
queue<int> q;
for (int i = 1; i <= n; i++) {
if (deg[i] == 1) {
q.push(i);
}
}
while (!q.empty()) {
// deg 1
auto cur = q.front(); q.pop();
seen[cur] = true;
deg[cur] = 0;
auto to = adj[cur][0];
if (seen[to.first]) continue;
ll weight = v[cur];
v[to.first] -= weight;
calc[to.second] = weight;
if (--deg[to.first] == 1) {
q.push(to.first);
}
}
if (m == n - 1) {
for (int i = 1; i <= m; i++) {
cout << calc[i] * 2 << "\n";
}
return 0;
}
if (m > n || m % 2 == 0) {
cout << 0 << endl;
return 0;
}
for (int i = 1; i <= n; i++) {
assert(deg[i] == 2);
}
}
