#include <bits/stdc++.h>
using namespace std;
char arr[105][105];
int a, b, c, d, n;
int sizes[50];
void solve() {
  int rr, cc;
  int dir;
  if (a & 1) {
    rr = b - 1;
    cc = 0;
    dir = -1;
  } else {
    rr = cc = 0;
    dir = 1;
  }
  char ch = 'a';
  for (int i = (int)(0); i < (int)(n); ++i) {
    while (sizes[i]--) {
      if (rr < 0 || (rr == b && cc < a) || (rr == d && cc >= a)) {
        cc++;
        dir *= -1;
        rr += dir;
      }
      arr[rr][cc] = ch;
      rr += dir;
    }
    ++ch;
  }
}
int main() {
  cin >> a >> b >> c >> d >> n;
  for (int i = (int)(0); i < (int)(n); ++i) cin >> sizes[i];
  memset(arr, 0, sizeof arr);
  solve();
  b = max(b, d);
  cout << "YES\n";
  for (int i = (int)(0); i < (int)(b); ++i) {
    for (int j = (int)(0); j < (int)(a + c); ++j)
      if (arr[i][j])
        putchar(arr[i][j]);
      else
        putchar('.');
    putchar('\n');
  }
}
