#include <bits/stdc++.h>
using namespace std;
using lint         = long long;
constexpr lint inf = 1LL << 60;
constexpr lint mod = 1000000007;

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    lint n, m;
    cin >> n >> m;
    lint a, b;
    cin >> a >> b;
    lint col = m / 2;
    lint row = n / 2;

    lint colr = m % 2;
    lint rowr = n % 2;

    vector<string> ret(n, string(m, '.'));
    if (colr == 1) {
        lint mx = 2 * min(row, b);
        for (int i = 0; i < mx; i += 2) {
            ret[i][m - 1]     = '^';
            ret[i + 1][m - 1] = 'v';
            b--;
        }
    }
    if (rowr == 1) {
        lint mx = 2 * min(col, a);
        for (int i = 0; i < mx; i += 2) {
            ret[n - 1][i]     = '<';
            ret[n - 1][i + 1] = '>';
            a--;
        }
    }
    if (a % 2 == 1 && b % 2 == 1 && n % 2 == 1 && m % 2 == 1) {
        if (2 * (a + b) == (n - 1) * (m - 1)) {
            a--, b--;
            ret[n - 3][m - 3] = '<';
            ret[n - 3][m - 2] = '>';
            ret[n - 2][m - 3] = '^';
            ret[n - 1][m - 3] = 'v';
            ret[n - 1][m - 2] = '<';
            ret[n - 1][m - 1] = '>';
        }
    }
    for (int i = 0; i < row * 2; i += 2) {
        for (int j = 0; j < col * 2; j += 2) {
            if (b > 0) {
                ret[i][j]     = '^';
                ret[i + 1][j] = 'v';
                b--;
                if (b > 0) {
                    ret[i][j + 1]     = '^';
                    ret[i + 1][j + 1] = 'v';
                    b--;
                }
            } else if (a > 0) {
                ret[i][j]     = '<';
                ret[i][j + 1] = '>';
                a--;
                if (a > 0) {
                    ret[i + 1][j]     = '<';
                    ret[i + 1][j + 1] = '>';
                    a--;
                }
            } else {
                break;
            }
        }
    }
    if (a + b > 0) {
        cout << "NO"
             << "\n";
    } else {
        cout << "YES"
             << "\n";
        for (auto &r : ret) {
            cout << r << "\n";
        }
    }
    return 0;
}