#include <bits/stdc++.h>
using namespace std;

int main(){
	ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
	int n, m, a, b;
	cin >> n >> m >> a >> b;
	int n2 = n & 1;
	int m2 = m & 1;
	if(a > (m / 2) * n){
		cout << "NO" << '\n';
		return 0;
	}
	if(b > (n / 2) * m){
		cout << "NO" << '\n';
		return 0;
	}
	if(a + b > n * m / 2){
		cout << "NO" << '\n';
		return 0;		
	}
	vector<string> s(n, string(m, '.'));
	if(m & 1){
		for(int i = 0; i + 1 < n; i += 2){
			if(b > 0){
				s[i][m-1] = '^';
				s[i+1][m-1] = 'v';
				b -= 1;
			}
		}
		m -= 1;
	}
	if(n & 1){
		for(int j = 0; j + 1 < m; j += 2){
			if(a > 0){
				s[n-1][j] = '<';
				s[n-1][j+1] = '>';
				a -= 1;
			}
		}
		n -= 1;
	}
	for(int i = 0; i + 1 < n; i += 2){
		for(int j = 0; j + 1 < m; j += 2){
			if(a >= 2 || (b <= 1 && a > 0)){
				s[i][j] = '<';
				s[i][j+1] = '>';
				a -= 1;
				if(a > 0){
					s[i+1][j] = '<';
					s[i+1][j+1] = '>';
					a -= 1;
				}
			} else if(b > 0){
				s[i][j] = '^';
				s[i+1][j] = 'v';
				b -= 1;
				if(b > 0){
					s[i][j+1] = '^';
					s[i+1][j+1] = 'v';
					b -= 1;
				}
			}
		}
	}
	if(a > 0 || b > 0){
		if(n2 & m2){
			s[n-2] = s[n-2].substr(0, m-2) + "<>^";
			s[n-1] = s[n-1].substr(0, m-2) + "^.v";
			s[n  ] = s[n  ].substr(0, m-2) + "v<>";			
		} else {
			cout << "NO" << '\n';
			return 0;
		}
	}
	cout << "YES" << '\n';
	for(string x : s){
		cout << x << '\n';
	}
}