#include<bits/stdc++.h>
#define ll long long
#define pb push_back
#define mr make_pair
using namespace std;
int m,n,x,y,wz,X,Y,Z;
char an[1010][1010];
int main(){
	cin>>n>>m>>x>>y;
	for (int i=1;i<=n;i++)
		for (int j=1;j<=m;j++)an[i][j]='.';
	wz=(n/2)*(m/2);
	X=(n%2)*(m/2);Y=(n/2)*(m%2);Z=(n%2)*(m%2)*(max(x-X,0)%2)*(max(y-Y,0)%2);
	if (max(x-X+1,0)/2+max(y-Y+1,0)/2-Z>wz)puts("NO");
	else{
		puts("YES");
		for (int i=1;i<=min(x,X);i++){an[n][i*2-1]='<';an[n][i*2]='>';}
		x-=min(x,X);
		for (int i=1;i<=min(y,Y);i++){an[i*2-1][m]='^';an[i*2][m]='v';}
		y-=min(y,Y);
		for (int i=1;i<=n/2;i++){
			for (int j=1;j<=m/2;j++){
				if (x>=2){
					x-=2;an[i*2-1][j*2-1]='<';an[i*2-1][j*2]='>';
					an[i*2][j*2-1]='<';an[i*2][j*2]='>';
				}else{
					if (y){
						y--;an[i*2-1][j*2-1]='^';an[i*2][j*2-1]='v';
						if (y){y--;an[i*2-1][j*2]='^';an[i*2][j*2]='v';}
					}else{
						if (x){x--;an[i*2][j*2-1]='<';an[i*2][j*2]='>';}
					}
				}
			}
		}
		if (x){
			an[n][m]='v';an[n-1][m]='^';
			an[n-2][m-1]='<';an[n-2][m]='>';
		}
		for (int i=1;i<=n;i++){
			for (int j=1;j<=m;j++)putchar(an[i][j]);
			puts("");
		}
	}
	return 0;
}