#include <bits/stdc++.h>
using namespace std;
#define FOR(i, x, y) for (int i = x; i < y; i++)
#define pii pair<int, int>
#define f first
#define s second
const int mN = 1e5 + 5, mM = 5e5 + 5;
int n, m, cnt, st; long long A[mN], ans[mM], altSm; bool vis[mN]; set<pii> adj[mN];
void compressLeaves(){
queue<int> q;
FOR(i, 0, n) if (adj[i].size() == 1) q.push(i);
while (!q.empty()){
int cur = q.front(); q.pop();
if (adj[cur].empty()) continue;
pii nxt = *adj[cur].begin();
ans[nxt.s] = A[cur] * 2; A[nxt.f] -= A[cur];
adj[cur].clear(); adj[nxt.f].erase({cur, nxt.s});
if (adj[nxt.f].size() == 1) q.push(nxt.f);
}
}
void dfs(int cur, bool parity){
altSm += !parity ? A[cur] : -A[cur]; vis[cur] = 1;
for (pii nxt : adj[cur]) if (!vis[nxt.f]){
dfs(nxt.f, !parity);
}
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0);
cin >> n >> m;
FOR(i, 0, n) cin >> A[i];
FOR(i, 0, m){
int a, b; cin >> a >> b; a--; b--;
adj[a].insert({b, i}); adj[b].insert({a, i});
}
compressLeaves();
FOR(i, 0, n){
if (adj[i].size() == 2) st = i, cnt++;
if (adj[i].size() > 2){ cout<<0<<"\n"; return 0; }
}
if (cnt and cnt % 2 == 0){ cout<<0<<"\n"; return 0; }
if (cnt){
dfs(st, 0);
pii rem = *prev(adj[st].end());
A[st] -= altSm / 2; A[rem.f] -= altSm / 2;
ans[rem.s] = altSm;
adj[st].erase(rem); adj[rem.f].erase({st, rem.s});
compressLeaves();
}
FOR(i, 0, m) cout<<ans[i]<<"\n";
}
