#include <bits/stdc++.h>
// #pragma GCC optimize ("O3")
// #pragma GCC target ("sse4")
using namespace std;

typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int,int> PII;

#define REP(i,n) for(int i=0;i<(n);++i)
#define FOR(i,a,b) for (int i=(a); i<(b); ++i)
#define FORD(i,a,b) for (int i=(a)-1; i>=(b); --i)

#define pb push_back
#define mp make_pair
#define st first
#define nd second

const int MOD = 1000000007;

char board[1005][1005];

int main() {
  // ios_base::sync_with_stdio(0);

  int N, M, A, B;
  scanf("%d%d%d%d", &N, &M, &A, &B);

  REP(i,N)REP(j,M) board[i][j] = '.';

  if (M%2) {
    for (int i = 0; i+1 < N; i += 2) {
      if (B > 0) {
        board[i][0] = '^';
        board[i+1][0] = 'v';
        --B;
      }
    }

    if (B % 2 && M > 1 && N >= 2) {
      board[N-2][M-1] = '^';
      board[N-1][M-1] = 'v';
      --B;
    }
  }

  REP(i,N-1)REP(j,M) {
    if (board[i][j] == '.' && board[i+1][j] == '.' && B > 0) {
      board[i][j] = '^';
      board[i+1][j] = 'v';
      --B;
    }
  }
  REP(i,N)REP(j,M-1) {
    if (board[i][j] == '.' && board[i][j+1] == '.' && A > 0) {
      board[i][j] = '<';
      board[i][j+1] = '>';
      --A;
    }
  }

  if (A > 0 || B > 0) {
    printf("NO\n");
    return 0;
  }

  printf("YES\n");
  REP(i,N) printf("%s\n", board[i]);
}
