#include <bits/stdc++.h>
using namespace std;
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
int n, m;
cin >> n >> m;
vector<long long> a(n);
for (int i = 0; i < n; i++) {
cin >> a[i];
}
vector<vector<array<int, 2>>> g(n);
for (int i = 0; i < m; i++) {
int x, y;
cin >> x >> y;
--x; --y;
g[x].push_back({y, i});
g[y].push_back({x, i});
}
if (m > n) {
cout << 0 << '\n';
return 0;
}
if (n == 1) {
cout << 2 * a[0] << '\n';
return 0;
}
if (m < n) {
vector<long long> res(m);
function<void(int, int)> Dfs = [&](int v, int pv) {
for (auto& e : g[v]) {
int u = e[0];
if (u == pv) {
continue;
}
Dfs(u, v);
if (a[u] != 0) {
res[e[1]] = 2 * a[u];
a[v] -= a[u];
}
}
};
Dfs(0, 0);
if (a[0] != 0) {
cout << 0 << '\n';
return 0;
}
for (int i = 0; i < m; i++) {
cout << res[i] << '\n';
}
return 0;
}
vector<int> deg(n);
for (int i = 0; i < n; i++) {
deg[i] = (int) g[i].size();
}
vector<int> que;
for (int i = 0; i < n; i++) {
if (deg[i] == 1) {
que.push_back(i);
}
}
auto orig = a;
vector<long long> res(m);
for (int b = 0; b < (int) que.size(); b++) {
int i = que[b];
for (auto& e : g[i]) {
int j = e[0];
deg[j] -= 1;
if (deg[j] == 1) {
que.push_back(j);
res[e[1]] = 2 * a[i];
a[j] -= a[i];
}
}
}
vector<int> cyc;
for (int i = 0; i < n; i++) {
if (deg[i] > 1) {
cyc.push_back(i);
}
}
if ((int) cyc.size() % 2 == 0) {
cout << 0 << '\n';
return 0;
}
vector<bool> was(n);
vector<long long> vals;
vector<int> ids;
function<void(int)> Dfs = [&](int v) {
was[v] = true;
vals.push_back(a[v]);
int back = -1;
bool found = false;
for (auto& e : g[v]) {
int u = e[0];
int i = e[1];
if (u == cyc[0]) {
back = i;
}
if (was[u] || deg[u] <= 1) {
continue;
}
found = true;
ids.push_back(i);
Dfs(u);
}
if (!found) {
ids.push_back(back);
}
};
Dfs(cyc[0]);
long long total = 0;
for (int i = 0; i < (int) vals.size(); i++) {
total = vals[i] - total;
}
if (total % 2 == 1) {
cout << 0 << '\n';
return 0;
}
total /= 2;
res[ids.back()] = 2 * total;
for (int i = 0; i < n; i++) {
for (auto& p : g[i]) {
if (p[1] == ids.back()) {
a[i] -= total;
}
}
}
was = vector<bool>(n, false);
Dfs = [&](int v) {
was[v] = true;
for (auto& p : g[v]) {
int u = p[0];
int i = p[1];
if (deg[u] <= 1 || was[u] || i == ids.back()) {
continue;
}
Dfs(u);
res[i] = 2 * a[u];
a[v] -= a[u];
a[u] = 0;
}
};
Dfs(cyc.back());
if (a != vector<long long>(n, 0LL)) {
cout << 0 << '\n';
return 0;
}
for (int i = 0; i < m; i++) {
cout << res[i] << '\n';
}
return 0;
}
