#include <bits/stdc++.h>
typedef long long int ll;
typedef long double ld;
#define pb push_back
#define pii pair < ll , ll >
#define F first
#define S second
#define endl '\n'
#define int long long
#define sync ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0)
#pragma GCC optimize ("Ofast")
#pragma GCC optimize ("unroll-loops")
#define kill(x) return cout<<x<<'\n', 0;
using namespace std;
const int N=2e5+100;
vector <int> g[N];
ll hi[N];
ll ans[N];
map <pii,int> mp;
ll val[N],par[N],vis[N];
ll ras1=0,ras2=0;
ll dfsd(ll v,ll p,ll h){
// cout << v << " " << p << " " << h << endl;
par[v]=p;
hi[v]=h;
for (auto u : g[v]){
if (u==p) continue;
if (hi[u]<hi[v] && hi[u]!=0){
ras1=v,ras2=u;
// cout << v << " " << u << endl;
continue;
}
if (hi[u]!=0) continue;
dfsd(u,v,h+1);
}
}
ll dfs(ll v,ll p){
for (auto u : g[v]){
if (u==p || vis[u]) continue;
dfs(u,v);
val[v]+=-val[u];
mp[{u,v}]=2*-val[u];
mp[{v,u}]=mp[{u,v}];
val[u]=0;
}
}
vector <pii> yal;
int32_t main(){
sync;
ll n,m;
cin >> n >> m;
for (int i=1;i<=n;i++){
cin >> val[i];
val[i]=-val[i];
}
for (int i=0;i<m;i++){
ll u,v;
cin >> u >> v;
g[u].pb(v);
g[v].pb(u);
yal.pb({u,v});
}
if (m>n) kill(0);
if (m==n-1){
dfs(1,1);
if (val[1]!=0) kill(0);
}
if (m==n){
dfsd(1,1,1);
vector <int> ras;
while(ras1!=ras2){
ras.pb(ras1);
vis[ras1]=1;
ras1=par[ras1];
}
ras.pb(ras2);
vis[ras2]=1;
for (int i=1;i<=n;i++){
if (vis[i]){
dfs(i,i);
}
}
ll t=ras.size();
if (t%2==0) kill(0);
for (int i=1;i<t;i++){
ll v=ras[i],u=ras[(i+1)%t];
val[u]+=-val[v];
mp[{u,v}]=2*-val[v];
mp[{v,u}]=2*-val[v];
val[v]=0;
}
ll o=val[ras[0]];
if (o%2!=0) kill(0);
o/=2;
o=-o;
for (int i=0;i<t;i++){
ll v=ras[i],u=ras[(i+1)%t];
if (i%2==0){
mp[{u,v}]+=2*o;
mp[{v,u}]+=2*o;
}
else{
mp[{u,v}]-=2*o;
mp[{v,u}]-=2*o;
}
}
}
for (pii v : yal){
cout << mp[v] << endl;
}
}
