#include <bits/stdc++.h>

using namespace std;

#define pb push_back
#define mp make_pair
#define forn(i, n) for (int i = 0; i < (int)(n); ++i)
typedef long long LL;
typedef pair<int, int> PII;

int n, m, a, b;

char s[1000][1005];

int main() {
    scanf("%d%d%d%d", &n, &m, &a, &b);
    forn(i, n) forn(j, m) {
        s[i][j] = '.';
    }
    forn(i, n) s[i][m] = '\0';
    if (m % 2 == 1) {
        for (int i = 0; i + 1 < n; i += 2) {
            if (b == 0) continue;
            --b;
            s[i][m - 1] = '^';
            s[i + 1][m - 1] = 'v';
        }
    }
    if (n % 2 == 1) {
        for (int i = m % 2; i + 1 < m; i += 2) {
            if (a == 0) continue;
            --a;
            s[n - 1][i] = '<';
            s[n - 1][i + 1] = '>';
        }
    }
    if (n > 1 && m > 1 && n % 2 == 1 && m % 2 == 1 && a % 2 == 1 && b % 2 == 1) {
        s[n - 2][0] = '^';
        s[n - 1][0] = 'v';
        s[n - 3][0] = '<';
        s[n - 3][1] = '>';
        --a;
        --b;
    }
    for (int i = 0; i + 1 < n; i += 2) {
        for (int j = 0; j + 1 < m; j += 2) {
            if (s[i][j] != '.' || s[i][j + 1] != '.') continue;
            if (s[i + 1][j] != '.' || s[i + 1][j + 1] != '.') continue;
            if (a > 0) {
                s[i][j] = '<';
                s[i][j + 1] = '>';
                if (--a > 0) {
                    s[i + 1][j] = '<';
                    s[i + 1][j + 1] = '>';
                    --a;
                }
            } else if (b > 0) {
                s[i][j] = '^';
                s[i + 1][j] = 'v';
                if (--b > 0) {
                    s[i][j + 1] = '^';
                    s[i + 1][j + 1] = 'v';
                    --b;
                }
            }
        }
    }
    if (a > 0 || b > 0) {
        puts("NO");
        return 0;
    }
    puts("YES");
    forn(i, n) printf("%s\n", s[i]);
    return 0;
}
