#include <iostream>
#include <cstdio>
#include <vector>
#include <queue>
#include <map>
using namespace std;
int n, m, child[100015], p[100015], tmp[100015];
bool vst[100015];
long long d[100015], res[500015];
vector<int> g[100015];
queue<int> q;
map<pair<int, int>, int> mp;
void dfs (int u, int pv)
{
vst[u] = 1;
child[u] = 0;
for (int i = 0; i < (int)g[u].size(); ++i)
{
int v = g[u][i];
if (v == pv) continue;
dfs(v, u);
child[u] += child[v] + 1;
p[v] = u;
}
}
void caseTree()
{
p[1] = -1;
dfs(1, -1);
for (int i = 2; i <= n; ++i)
if (child[i] == 0) q.push(i);
for (int i = 1; i <= n; ++i)
tmp[i] = child[i];
while (!q.empty())
{
int u = q.front(); q.pop();
d[p[u]] -= d[u];
child[p[u]] -= (tmp[u] + 1);
if (p[u] != -1) res[mp[{u, p[u]}]] = d[u];
if (child[p[u]] < 1 && p[u] != -1) q.push(p[u]);
}
for (int id = 1; id <= m; ++id)
cout << res[id] << '\n';
}
int main()
{
ios_base::sync_with_stdio(false); cin.tie(NULL);
//freopen("pipes.inp", "r", stdin);
//freopen("pipes.out", "w", stdout);
cin >> n >> m;
for (int i = 1; i <= n; ++i)
cin >> d[i],
d[i] *= 2;
for (int i = 0, u, v; i < m; ++i)
cin >> u >> v,
g[u].push_back(v),
g[v].push_back(u),
mp[{u, v}] = i + 1,
mp[{v, u}] = i + 1;
if (m == n - 1)
caseTree();
else cout << 0;
}
