#include<bits/stdc++.h>
using namespace std;
const long long inf = (long long) 1e18 + 10;
const int inf1 = (int) 1e9 + 10;
#define int long long
#define dbl long double
#define endl '\n'
#define sc second
#define fr first
#define mp make_pair
#define pb push_back
#define all(x) x.begin(), x.end()
const int maxn = 5e5+10;
int n, m, c[maxn], ans[maxn], gr[maxn];
vector<pair<int,int>> g[maxn];
void solve() {
cin >> n >> m;
if(m != n-1) {
assert(0);
cout << 0 << endl;
return;
}
for(int i = 1; i <= n; i++) {
cin >> c[i];
}
if(n == 2) {
cout << 2*c[1] << endl;
return;
}
for(int i = 1; i <= m; i++) {
int u,v; cin >> u >> v;
g[u].pb(mp(v,i));
g[v].pb(mp(u,i));
gr[u]++;
gr[v]++;
}
queue<int> q;
for(int i = 1; i <= n; i++) {
if(gr[i] == 1) q.push(i);
}
while(q.size()) {
int u = q.front(); q.pop();
gr[u] = -1;
for(auto V : g[u]) {
int v = V.fr;
int id = V.sc;
if(gr[v] == -1) continue;
ans[id] = 2*c[u];
c[v]-= c[u];
if(--gr[v] == 1) q.push(v);
}
}
for(int i = 1; i <= m; i++) {
cout << ans[i] << endl;
}
}
int32_t main() {
ios::sync_with_stdio(false); cin.tie(0);
// freopen("in.in", "r", stdin);
// freopen("out.out", "w", stdout);
int tt = 1;
// cin >> tt;
while(tt--) {
solve();
}
}
