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;
int n, m;
int color[100007];
vector<int> g[100007];
map<pair<int, int>, int> reb;
int root;
int was[100007];
vector<int> st;
vector<int> cyc;
long long ans[100007];
void dfs(int v, int col) {
  if (cyc.size()) return;
  st.push_back(v);
  was[v] = col;
  for (int to : g[v]) {
    if (cyc.size()) return;
    if (was[to] == -1) {
      dfs(to, col ^ 1);
    } else {
      if (was[to] == was[v] && cyc.size() == 0) {
        for (int i = (int)st.size() - 1; i >= 0; i--) {
          cyc.push_back(st[i]);
          if (st[i] == to) break;
        }
      }
    }
  }
  st.pop_back();
}
long long dfs2(int v) {
  was[v] = 1;
  long long now = color[v];
  for (int to : g[v])
    if (was[to] == -1) {
      long long val = dfs2(to);
      ans[reb[make_pair(v, to)]] += val;
      now -= val;
    }
  return now;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> n >> m;
  for (int i = 0; i < n; i++) cin >> color[i];
  for (int i = 0; i < m; i++) {
    int a, b;
    cin >> a >> b;
    a--;
    b--;
    g[a].push_back(b);
    g[b].push_back(a);
    reb[make_pair(a, b)] = i;
    reb[make_pair(b, a)] = i;
  }
  for (int i = 0; i < n; i++) was[i] = -1;
  dfs(0, 0);
  for (int i = 0; i < n; i++) was[i] = -1;
  if (cyc.size() == 0)
    root = 0;
  else
    root = cyc.back();
  long long ww = dfs2(root);
  if (ww != 0) {
    if (abs(ww) % 2 == 1 || cyc.size() == 0) cout << "NO", exit(0);
    long long val = ww / 2;
    int ff = 0;
    ans[reb[make_pair(cyc[0], cyc.back())]] += val;
    for (int i = 0; i < (int)cyc.size() - 1; i++) {
      if (ff == 0)
        ans[reb[make_pair(cyc[i], cyc[i + 1])]] -= val;
      else
        ans[reb[make_pair(cyc[i], cyc[i + 1])]] += val;
      ff ^= 1;
    }
  }
  cout << "YES\n";
  for (int i = 0; i < m; i++) cout << ans[i] << ' ';
}
