#include <algorithm>
#include <bitset>
#include <cassert>
#include <chrono>
#include <climits>
#include <cmath>
#include <complex>
#include <cstring>
#include <deque>
#include <functional>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include <cstdint>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef pair<int,int> pii;
#define MP make_pair
#define PB push_back
#define inf 1000000007
#define mod 1000000007
#define rep(i,n) for(int i = 0; i < (int)(n); ++i)
#define all(x) (x).begin(),(x).end()

template<typename A, size_t N, typename T>
void Fill(A (&array)[N], const T &val){
    std::fill( (T*)array, (T*)(array+N), val );
}
 
template<class T> inline bool chmax(T &a, T b){
    if(a<b){
        a = b;
        return true;
    }
    return false;
}

template<class T> inline bool chmin(T &a, T b){
    if(a>b){
        a = b;
        return true;
    }
    return false;
}
char a[1010][1010];
int main(){
    int n,m;
    cin >> n >> m;
    
    rep(i,n){
        rep(j,m)a[i][j] = '.';
    }
    int A,B;
    cin >> A >> B;
    if(n==1&&m==1){
        if(A==0&&B==0){
            cout << "YES" << endl;
            cout << "." << endl;
        }else{
            cout << "NO" << endl;
        }
        return 0;
    }
    if(n==1){
        if(B>0){
            cout << "NO" << endl;
            return 0;
        }
        for(int i=0;i<m-1;i+=2){
            if(A==0)break;
            A--;
            a[0][i] = '<';
            a[0][i+1] = '>';
        }
    }else if(m==1){
        if(A>0){
            cout << "NO" << endl;
            return 0;
        }
        for(int i=0;i<n-1;i+=2){
            if(B==0)break;
            B--;
            a[i][0] = '^';
            a[i+1][0] = 'v';
        }
    }else if(n%2==1&&m%2==1){
        for(int i=0;i<n-3;i+=2){
            if(B>0){
                a[i][m-1] = '^';
                a[i+1][m-1] = 'v';
                B--;
            }
        }
        for(int i=0;i<m-3;i+=2){
            if(A>0){
                a[n-1][i] = '<';
                a[n-1][i+1] = '>';
                A--;
            }
        }
        vector<pii> p;
        for(int i=0;i<n-1;i+=2){
            for(int j=0;j<m-1;j+=2){
                if(i==n-3&&j==m-3)continue;
                p.push_back(MP(i,j));
            }
        }
        for(auto x:p){
            int i = x.first;
            int j = x.second;
            if(A>2){
                a[i][j] = '<';
                a[i][j+1] = '>';
                a[i+1][j] = '<';
                a[i+1][j+1] = '>';
                A-=2;
            }else if(B>2){
                a[i][j] = '^';
                a[i][j+1] = '^';
                a[i+1][j] = 'v';
                a[i+1][j+1] = 'v';
                B-=2;
            }
        }
        if(A==0){
            for(int j=0;j<min(B,3);j++){
                a[n-2][m-3+j] = '^';
                a[n-1][m-3+j] = 'v';
            }
            B -= min(B,3);
        }else if(A==1){
            A = 0;
            a[n-3][m-3] = '<';
            a[n-3][m-2] = '>';
            for(int j=0;j<min(B,3);j++){
                a[n-2][m-3+j] = '^';
                a[n-1][m-3+j] = 'v';
            }
            
            B -= min(B,3);
        }else if(A==2){
            A = 0;
            a[n-3][m-3] = '<';
            a[n-3][m-2] = '>';
            a[n-1][m-2] = '<';
            a[n-1][m-1] = '>';
            if(B>0){
                B--;
                a[n-2][m-3] = '^';
                a[n-1][m-3] = 'v';
                if(B>0){
                    B--;
                    a[n-3][m-1] = '^';
                    a[n-2][m-1] = 'v';
                }
            }
        }else if(A==3){
            A = 0;
            for(int j=0;j<3;j++){
                a[n-3+j][m-3] = '<';
                a[n-3+j][m-2] = '>';
            }
            if(B>0){
                B--;
                a[n-3][m-1] = '^';
                a[n-2][m-1] = 'v';
            }
        }
    }else if(n%2==1){
        for(int i=0;i<m;i+=2){
            if(A>0){
                a[n-1][i] = '<';
                a[n-1][i+1] = '>';
                A--;
            }
        }
        vector<pii> p;
        for(int i=0;i<n-1;i+=2){
            for(int j=0;j<m;j+=2){
                p.push_back(MP(i,j));
            }
        }
        for(auto x:p){
            int i = x.first;
            int j = x.second;
            if(A>0){
                a[i][j] = '<';
                a[i][j+1] = '>';
                A--;
                if(A>0){
                    a[i+1][j] = '<';
                    a[i+1][j+1] = '>';
                    A--;
                }
            }else if(B>0){
                a[i][j] = '^';
                    a[i+1][j] = 'v';
                
                B--;
                if(B>0){
                a[i][j+1] = '^';
                    a[i+1][j+1] = 'v';
                    B--;
                }
            }
        }
    }else if(m%2==1){
        for(int i=0;i<n;i+=2){
            if(B>0){
                a[i][m-1] = '^';
                a[i+1][m-1] = 'v';
                B--;
            }
        }
        vector<pii> p;
        for(int i=0;i<n;i+=2){
            for(int j=0;j<m-1;j+=2){
                p.push_back(MP(i,j));
            }
        }
        for(auto x:p){
            int i = x.first;
            int j = x.second;
            if(A>0){
                a[i][j] = '<';
                a[i][j+1] = '>';
                A--;
                if(A>0){
                    a[i+1][j] = '<';
                    a[i+1][j+1] = '>';
                    A--;
                }
            }else if(B>0){
                a[i][j] = '^';
                a[i+1][j] = 'v';    
                B--;
                if(B>0){
                    a[i][j+1] = '^';
                    a[i+1][j+1] = 'v';
                    B--;
                }
            }
        }
    }else{
        vector<pii> p;
        for(int i=0;i<n;i+=2){
            for(int j=0;j<m;j+=2){
                p.push_back(MP(i,j));
            }
        }
        for(auto x:p){
            int i = x.first;
            int j = x.second;
            if(A>0){
               a[i][j] = '<';
                a[i][j+1] = '>';
                A--;
                if(A>0){
                    a[i+1][j] = '<';
                    a[i+1][j+1] = '>';
                    A--;
                }
            }else if(B>0){
                a[i][j] = '^';
                a[i+1][j] = 'v';    
                B--;
                if(B>0){
                    a[i][j+1] = '^';
                    a[i+1][j+1] = 'v';
                    B--;
                }
            }
        }
    }
    if(A>0||B>0){
        cout << "NO\n";
    }else{
        cout << "YES\n";
        rep(i,n){
            rep(j,m){
                cout << a[i][j];
            }
            cout << "\n";
        }
    }
    return 0;
}

Measured memory_bytes: 3444