#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef pair<int,int> pii;
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define sz(a) int(a.size())
const int N=1e3+10;

int gi() {
	int x=0,o=1;char ch=getchar();
	while((ch<'0'||ch>'9')&&ch!='-') ch=getchar();
	if(ch=='-') o=-1,ch=getchar();
	while(ch>='0'&&ch<='9') x=x*10+ch-'0',ch=getchar();
	return x*o;
}

int n,m,a,b;
char s[N][N];

int main() {
	cin>>n>>m>>a>>b;
	memset(s,'.',sizeof(s));
	if(n&1) {
		for(int i=1;i<m&&a;i+=2) --a,s[n][i]='<',s[n][i+1]='>';
	}
	if(m&1) {
		for(int i=1;i<n&&b;i+=2) --b,s[i][m]='^',s[i+1][m]='v';
	}
	for(int i=1;i<n;i+=2)
		for(int j=1;j<m;j+=2) {
			if(a>=2) {
				a-=2;
				s[i][j]=s[i+1][j]='<';
				s[i][j+1]=s[i+1][j+1]='>';
			}
			else if(b>=2) {
				b-=2;
				s[i][j]=s[i][j+1]='^';
				s[i+1][j]=s[i+1][j+1]='v';
			}
			else if(i==n-2&&j==m-2&&a&&b) {
				--a;--b;
				s[i][j]=s[i+2][j+1]='<';
				s[i][j+1]=s[i+2][j+2]='>';
				s[i][j+2]=s[i+1][j]='^';
				s[i+1][j+2]=s[i+2][j]='v';
			}
			else if(a) {
				--a;
				s[i][j]='<';s[i][j+1]='>';
			}
			else if(b) {
				--b;
				s[i][j]='^';s[i+1][j]='v';
			}
		}
	if(a||b) cout<<"NO";
	else {
		cout<<"YES\n";
		for(int i=1;i<=n;i++,putchar('\n'))
			for(int j=1;j<=m;j++) putchar(s[i][j]);
	}
	return 0;
}
