#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define N 600005
#define ff first
#define ss second
#define pb push_back
#define sz(s) (int)s.size()
ll n, m, par[N], a[N], viss[N], c[N], sum;
vector <ll> v[N], e;
vector <pair <ll,ll>> ans;
map <pair<ll,ll>,ll> vip;
void solve(int x) {
viss[x] = 1;
for(auto i : v[x]) {
if(viss[i] == 1 && par[x] != i) {
int cnt = 1;
e.pb(i);
while(x != par[x]) {
sum += a[x];
e.pb(x);
cnt++;
c[x] = 1;
x = par[x];
}
e.pb(x);
reverse(e.begin(),e.end());
sum += a[x];
c[x] = 1;
if(cnt % 2 == 0) {
cout << "0\n";
exit(0);
}
continue;
}
if(viss[i]) continue;
par[i] = x;
solve(i);
if(!c[i]) {
ans.pb({vip[{x,i}],a[i]});
a[x] -= a[i];
}
}
}
int main () {
ios::sync_with_stdio(0);cin.tie(0);
cin >> n >> m;
for(int i = 1;i <= n; i++) {
cin >> a[i];
}
for(int i = 1;i <= m; i++) {
ll x, y;
cin >> x >> y;
v[x].pb(y);
v[y].pb(x);
vip[{x,y}] = i;
vip[{y,x}] = i;
}
if(n < m) {
cout << '0' << '\n';
return 0;
}
solve(1);
sum /= 2;
for(int i = 0; i < sz(e)-1; i++) {
ans.pb({vip[{e[i],e[i+1]}],sum});
sum = a[e[i + 1]] - sum;
}
sort(ans.begin(),ans.end());
for(auto i:ans) {
cout << i.ss * 2 << '\n';
}
}
