#include<iostream>
#include<cstdio>
#include<cstring>

const int N=1010;

char s[N][N];

int n,m,S,Sa,Sb;
int A,B;

bool construct1()
{
	memset(s,0,sizeof(s));
	int a=A,b=B;
	if(n&1)
	{
		for(int i=1;a && i<m;i+=2)
			s[n][i]='<',s[n][i+1]='>',a--;
	}
	if(m&1)
	{
		for(int i=1;b && i<n;i+=2)
			s[i][m]='^',s[i+1][m]='v',b--;
	}
	int x=1,y=1;
	while(a>0)
	{
		if(x>=n)return 0;

		s[x][y]='<',s[x][y+1]='>',a--;
		if(a)s[x+1][y]='<',s[x+1][y+1]='>',a--;

		y+=2;if(y>=m)x+=2,y=1;
	}
	while(b>0)
	{
		if(x>=n)return 0;

		s[x][y]='^',s[x+1][y]='v',b--;
		if(b)s[x][y+1]='^',s[x+1][y+1]='v',b--;

		y+=2;if(y>=m)x+=2,y=1;
	}

	return 1;
}

bool construct2()
{
	memset(s,0,sizeof(s));
	int a=A,b=B;

	if(a<2 || b<2)return 0;

	s[n-2][m-2]='<',s[n-2][m-1]='>',s[n-2][m]='^';
	s[n-1][m-2]='^',s[n-1][m-1]='.',s[n-1][m]='v';
	s[n][m-2]  ='v',s[n][m-1]  ='<',s[n][m]  ='>';

	a-=2,b-=2;
	for(int i=1;a && i<m-2;i+=2)
		s[n][i]='<',s[n][i+1]='>',a--;
	for(int i=1;b && i<n-2;i+=2)
		s[i][m]='^',s[i+1][m]='v',b--;

	int x=1,y=1;
	while(a>0)
	{
		if(x==n-2 && y==m-2)return 0;

		s[x][y]='<',s[x][y+1]='>',a--;
		if(a>0)s[x+1][y]='<',s[x+1][y+1]='>',a--;

		y+=2;if(y>=m)x+=2,y=1;
	}
	while(b>0)
	{
		if(x==n-2 && y==m-2)return 0;

		s[x][y]='^',s[x+1][y]='v',b--;
		if(b>0)s[x][y+1]='^',s[x+1][y+1]='v',b--;

		y+=2;if(y>=m)x+=2,y=1;
	}

	return 1;
}

int main()
{
	scanf("%d%d%d%d",&n,&m,&A,&B);
	S=(n*m)/2;
	Sa=(m/2)*n;
	Sb=(n/2)*m;

	bool flag=1;

	if(A+B>S || A>Sa || B>Sb)flag=0;
	else if((n*m)&1)flag=construct1() || construct2();
	else flag=construct1();

	if(!flag)printf("NO\n");
	else
	{
		printf("YES\n");
		for(int i=1;i<=n;i++,printf("\n"))
			for(int j=1;j<=m;j++)printf("%c",s[i][j]?s[i][j]:'.');
	}

	return 0;
}
