///huynhocute123///
#include<bits/stdc++.h>
using namespace std;
#define S second
#define F first
#define pii pair<int,int>
#define piii pair<int,pair<int,int>>
#define pb push_back
#define pi M_PI
#define FOR(i, a, b) for(int i = a; i <= b; ++i)
#define REP(i, a, b) for(int i = b; i >= a; --i)
#define ALL(v) v.begin(),v.end()
#define inp(name) if(fopen(name, "r")) freopen(name, "r", stdin);
#define out(name) if(fopen(name, "w")) freopen(name, "w", stdout);
//random_device rd;
//mt19937 rng(rd());
//#pragma GCC optimize ("O3")
//#pragma GCC optimize ("unroll-loops")
//#pragma GCC target("popcnt")
//#define int long long
const int maxN = 1e5 + 9 ;
const int modd = 1e9 + 7;
const int base = 2309;
const int MAX = 1e9+9;
void minimize(int &u, int v){
if(v < u) u = v;
}
void maximize(int &u, int v){
if(v > u) u = v;
}
int n, k, t, m, res, a[maxN], ans[maxN], deg[maxN];
int l, r;
bool vis[maxN];
vector<pii> e[maxN];
namespace sub1{
void dfs(int u ,int p){
for(auto [x, id] : e[u]){
if(x == p)continue;
dfs(x , u);
ans[id]= a[x];
a[u] -= a[x];
}
}
void solve(){
dfs(1, 0);
FOR(i, 1, m)cout << ans[i] *2 <<'\n';
}
}
namespace sub2{
queue<int> q;
void solve(){
FOR(i, 1, n){
if(deg[i] == 1){
q.push(i);
vis[i] =1;
// cout << i << " ";
}
}
// cout <<endl;
while(!q.empty()){
int u = q.front();
// cout << u << " ";
q.pop();
vis[u] =1;
for(auto [x, id ] : e[u]){
if(vis[x])continue;
ans[id] = a[u];
// cout << id << " " << a[u] <<'\n';
a[x]-=a[u];
// vis[x] = 1;
deg[x]--;
if(deg[x] == 1)q.push(x);
}
}
int cnt =0;
FOR(i, 1, n){
if(!vis[i]){
q.push(i);
cnt++;
}
}
if(cnt %2 ==0){
cout << 0;
return;
}
FOR(i, 1, m)cout << ans[i] *2 <<'\n';
}
}
void solve(){
cin >> n >> m;
FOR(i, 1, n)cin >> a[i];
FOR(i, 1, m){
cin >> l >> r;
e[l].pb({r, i});
e[r].pb({l, i});
deg[l]++;
deg[r]++;
}
if(m > n ){
cout << 0;
return;
}
if(m == n)sub2::solve();
else sub1::solve();
}
signed main(){
// freopen("name.inp","r",stdin);
// freopen("name.out","w",stdout);
ios_base::sync_with_stdio(false);
cin.tie(0);
inp("task.inp");
t = 1;
// cin >> t;
while( t-- )solve();
}
