#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int a, b, c, d;
  int n;
  cin >> a >> b >> c >> d >> n;
  vector<int> v(n);
  for (int i = 0; i < n; i++) {
    cin >> v[i];
  }
  cout << "YES\n";
  int row = max(b, d);
  int col = a + c;
  char ans[row][col];
  for (int i = 0; i < row; i++) {
    for (int j = 0; j < col; j++) {
      ans[i][j] = '.';
    }
  }
  int x, y, yc;
  int dir;
  if (d % 2 == 1) {
    y = a + c - 1;
    yc = a;
    x = d - 1;
    dir = -1;
  } else {
    y = a;
    yc = a + c - 1;
    x = d - 1;
    dir = 1;
  }
  int ind = 0;
  for (int i = x; i >= 0; i--) {
    for (int j = y; j < a + c and j > a - 1; j += dir) {
      if (v[ind]) {
        ans[i][j] = 'a' + ind;
        v[ind]--;
      } else {
        ind++;
        j -= dir;
      }
    }
    dir = (dir == 1) ? -1 : 1;
    swap(y, yc);
  }
  dir = -1;
  y = a - 1;
  yc = 0;
  for (int i = 0; i < b; i++) {
    for (int j = y; j < a and j >= 0; j += dir) {
      if (v[ind]) {
        ans[i][j] = 'a' + ind;
        v[ind]--;
      } else {
        ind++;
        j -= dir;
      }
    }
    dir = (dir == 1) ? -1 : 1;
    swap(y, yc);
  }
  for (int i = 0; i < row; i++) {
    for (int j = 0; j < col; j++) {
      cout << ans[i][j];
    }
    cout << endl;
  }
}
