2 1
1 1
2 1
 8 12
-6 2 -3 2 6 -7 1 -5
2 1
5 6
1 6
1 4
8 2
2 7
2 5
8 3
8 4
3 7
7 6
3 1
 10 13
3 4 -3 8 6 4 -5 1 3 -7
9 5
9 2
10 3
1 4
3 5
9 1
6 10
10 4
3 1
2 7
1 6
1 7
7 8
 43 52
-23 -18 -35 21 -12 38 -35 -11 28 -20 27 -5 9 -19 -39 -25 -32 32 -36 28 11 37 1 -25 -22 9 -15 21 25 -39 10 36 -30 -40 22 26 25 -27 -22 -38 -1 18 -13
33 40
31 23
30 26
21 17
6 2
41 19
32 39
32 23
13 14
25 35
31 30
19 32
25 22
34 36
7 40
23 6
40 12
1 3
23 43
36 13
18 33
17 32
7 3
21 34
41 35
20 7
23 1
41 8
25 19
20 29
42 5
40 21
9 37
17 41
30 10
41 18
39 1
20 24
20 4
42 3
20 25
5 16
31 9
42 28
10 11
19 42
31 38
25 2
31 27
17 25
13 15
31 20
 2 1
1 1
1 2
 5 7
4 1 5 3 -1
2 4
5 4
5 2
1 5
1 2
4 1
1 3
 10 12
5 1 1 8 -8 10 -3 -2 1 7
5 3
8 2
10 9
4 6
5 6
4 5
5 10
4 7
8 4
3 1
3 6
6 10
 20 40
-9 -10 -9 15 -3 -5 -17 -10 -6 2 -13 19 10 -15 15 -14 17 0 7 -8
3 17
6 18
15 12
2 5
18 3
16 20
6 17
20 10
10 18
9 12
15 3
6 4
15 16
20 6
20 9
9 4
4 8
14 5
11 7
12 11
3 13
14 19
7 17
16 14
19 7
12 13
14 13
13 11
9 14
13 17
8 19
5 20
2 17
2 16
12 5
8 1
20 3
6 2
5 18
13 8

YES
                                                               1
 NO
 YES
                                                              -7
                                                              10
                                                             -16
                                                               3
                                                              13
                                                               0
                                                               4
                                                               5
                                                               0
                                                              -6
                                                               0
                                                               0
                                                               1
 NO
 YES
                                                               1
 YES
                                                               2
                                                               1
                                                              -1
                                                              -1
                                                               0
                                                               0
                                                               5
 YES
-4
1
1
17
-7
-3
6
-3
-3
5
0
0
 YES
                                                             -30
                                                             -21
                                                             -23
                                                             -10
                                                              21
                                                             -52
                                                               0
                                                               2
                                                               0
                                                              -9
                                                               0
                                                              16
                                                              38
                                                               0
                                                              42
                                                               0
                                                              -1
                                                               7
                                                             -64
                                                              51
                                                               0
                                                               7
                                                              47
                                                               0
                                                               0
                                                               0
                                                              10
                                                               0
                                                             -39
                                                               0
                                                               0
                                                               0
                                                               0
                                                               0
                                                               0
                                                              -9
                                                               0
                                                               0
                                                               0
                                                               0

#include <bits/stdc++.h>
using namespace std;
const long long N = 1e5 + 9;
vector<pair<long long, long long> > adj[N];
long long a[N], mrk[N], is = 1, root = 1, sum[N], ans[N];
vector<long long> cyc;
pair<long long, long long> par[N];
void DFS1(long long u) {
  for (pair<long long, long long> v : adj[u]) {
    if (!mrk[v.first]) {
      mrk[v.first] = 3 - mrk[u];
      par[v.first] = {u, v.second};
      DFS1(v.first);
    } else if (is && mrk[v.first] == mrk[u]) {
      is = 0, root = u;
      long long x = u;
      while (x != v.first) {
        cyc.push_back(par[x].second);
        x = par[x].first;
      }
      cyc.push_back(v.second);
    }
  }
}
void DFS2(long long u) {
  mrk[u] = 1;
  for (pair<long long, long long> v : adj[u]) {
    if (!mrk[v.first]) {
      DFS2(v.first);
      ans[v.second] = a[v.first] - sum[v.first];
      sum[u] += ans[v.second];
    }
  }
}
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  long long n, m;
  cin >> n >> m;
  for (long long i = 1; i <= n; i++) cin >> a[i];
  for (long long i = 0; i < m; i++) {
    long long u, v;
    cin >> u >> v;
    adj[u].push_back({v, i});
    adj[v].push_back({u, i});
  }
  mrk[1] = 1;
  DFS1(1);
  fill(mrk, mrk + N, 0);
  DFS2(root);
  if (is && a[root] != sum[root]) return cout << "NO", 0;
  cout << "YES" << endl;
  if (!is)
    for (long long i = 0, t = 1; i < cyc.size(); i++, t *= -1)
      ans[cyc[i]] += t * (a[root] - sum[root]) / 2;
  for (long long i = 0; i < m; i++) cout << ans[i] << " ";
  return 0;
}
