#include <bits/stdc++.h>
#define pb push_back
#define fi first
#define se second
#define pii pair<int, int>
#define pipii pair<int, pair<int, int>>
#define vi vector<int>
#define vpi vector<pair<int, int>>
#define inp(name) if(fopen(name, "r")) freopen(name, "r", stdin);
#define out(name) if(fopen(name, "w")) freopen(name, "w", stdout);
#define int long long
const int N = 1e6 + 5;
const int mod = 1e9 + 7;
using namespace std;
long long n, m, c[N], ans[N];
vpi ad[N];
void dfs(int u, int p, int id = 0)
{
long long res = 0;
for(auto [v, pos] : ad[u])
{
if(v == p) continue ;
dfs(v, u, pos);
res += ans[pos];
}
ans[id] = c[u] - res;
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(0);
cin >> n >> m;
for(int i = 1; i <= n; ++i)
{
cin >> c[i];
}
for(int i = 1; i <= m; ++i)
{
int u, v;
cin >> u >> v;
ad[u].pb({v, i});
ad[v].pb({u, i});
}
if(m != (n-1))
{
cout << 0;
return 0;
}
dfs(1, 0);
for(int i = 1; i <= m; ++i)
{
cout << 2*ans[i] << "\n";
}
return 0;
}
