#include<bits/stdc++.h>
using namespace std;
int n, m, a, b;
char o[1005][1005];

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