#include <iostream>
#include <cstdio>
#include <vector>
#include <map>
using namespace std;
int n, m, child[100015], p[100015];
bool vst[100015];
long long d[100015], res[500015];
vector<int> g[100015];
map<pair<int, int>, int> mp;
void dfs (int u)
{
vst[u] = 1;
child[u] = 0;
for (int i = 0; i < (int)g[u].size(); ++i)
{
int v = g[u][i];
if (!vst[v])
{
dfs(v);
child[u] += 1 + child[v];
p[v] = u;
}
}
}
void caseTree()
{
dfs(1);
while (child[1] > 0)
{
for (int u = 1; u <= n; ++u)
if (child[u] == 0)
{
d[p[u]] -= d[u];
--child[p[u]];
res[mp[{u, p[u]}]] = d[u];
child[u] = -1;
}
}
if (d[1] != 0) cout << 0;
else
{
for (int id = 0; id < m; ++id)
cout << res[id] << '\n';
}
}
int main()
{
ios_base::sync_with_stdio(false); cin.tie(NULL);
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,
mp[{v, u}] = i;
if (m == n - 1)
caseTree();
else if (n < m)
cout << 0;
}
