#include <bits/stdc++.h>
using namespace std;
#define int long long
#define ld long double
#define ll long long
#define P pair<int,int>
#define fi first
#define se second
#define rep(i,n) for(int i=0;i<n;i++)
#define all(v) v.begin(),v.end()
#define pb push_back
#define eb emplace_back
template<class T>void chmax(T &a,T b){if(a<b)a=b;}
template<class T>void chmin(T &a,T b){if(a>b)a=b;}
constexpr int INF=1000000000000000000;
constexpr int mod=1000000007;
constexpr double eps=1e-8;
const double pi=acos(-1);
int dx[]={0,1,0,-1},dy[]={1,0,-1,0};
int Random(int mi,int ma){
    random_device rnd;
    mt19937 mt(rnd());//32bit
    //[mi,ma]
    uniform_int_distribution<int>engine(mi,ma);
    return engine(mt);
}
int gcd(int a,int b){
    if(b==0)return a;
    return gcd(b,a%b);
}
int lcm(int a,int b){
    return a/gcd(a,b)*b;
}
bool prime(int a){
    if(a==1)return false;
    for(int i=2;i*i<=a;i++){
        if(a%i==0)return false;
    }
    return true;
}
int modpow(int a,int b){
    if(b==0)return 1;
    if(b%2)return modpow(a,b-1)*a%mod;
    int memo=modpow(a,b/2);
    return memo*memo%mod;
}
vector<int>kaijo,invkaijo;
void init_fact(int n){
    kaijo.resize(n+1);
    invkaijo.resize(n+1);
    kaijo[0]=1;
    for(int i=1;i<=n;i++){
        kaijo[i]=kaijo[i-1]*i;
        kaijo[i]%=mod;
    }
    rep(i,n+1)invkaijo[i]=modpow(kaijo[i],mod-2);
}
int comb(int a,int b){
    if(a<b)return 0;
    if(a<0||b<0)return 0;
    return kaijo[a]*invkaijo[a-b]%mod*invkaijo[b]%mod;
}
int inv(int x){
    x=modpow(x,mod-2);
    return x;
}

void solve(){
    int n,m,a,b;
    cin>>n>>m>>a>>b;
    char c[1010][1010];
    rep(i,n)rep(j,m)c[i][j]='.';
    if(n*m<2*(a+b)){
        puts("NO");
        return;
    }
    int cnta=0,cntb=0;
    bool corner=(n%2==1&&m%2==1&&(n*m-1)==2*(a+b)&&(n-1)*m/2%2!=b%2);
    if(m%2==1){
        if((m-1)*n/2<a){
            puts("NO");
            return;
        }
        rep(i,n/2){
            if(i==n/2-1&&corner)continue;
            if(cntb<b){
                c[i*2][m-1]='^';
                c[i*2+1][m-1]='v';
                cntb++;
            }
        }
    }
    if(n%2==1){
        if((n-1)*m/2<b){
            puts("NO");
            return;
        }
        rep(j,m/2){
            if(j==m/2-1&&corner)continue;
            if(cnta<a){
                c[n-1][j*2]='<';
                c[n-1][j*2+1]='>';
                cnta++;
            }
        }
    }
    rep(i,n/2){
        rep(j,m/2){
            if(i==n/2-1&&j==m/2-1&&corner)continue;
            if(cnta+(corner?2:0)<a){
                c[i*2][j*2]='<';
                c[i*2][j*2+1]='>';
                c[i*2+1][j*2]='<';
                c[i*2+1][j*2+1]='>';
                cnta+=2;
            }
            else if(cntb+(corner?2:0)<b){
                c[i*2][j*2]='^';
                c[i*2+1][j*2]='v';
                c[i*2][j*2+1]='^';
                c[i*2+1][j*2+1]='v';
                cntb+=2;
            }
        }
    }
    if(corner){
        c[n-3][m-3]='<';
        c[n-3][m-2]='>';
        c[n-3][m-1]='^';
        c[n-2][m-3]='^';
        c[n-2][m-2]='.';
        c[n-2][m-1]='v';
        c[n-1][m-3]='v';
        c[n-1][m-2]='<';
        c[n-1][m-1]='>';
        cnta=a,cntb=b;
    }
    if(cnta<a||cntb<b){
        puts("NO");
        return;
    }
    rep(i,n){
        rep(j,m){
            if(cnta>a&&c[i][j]=='<'){
                c[i][j]=c[i][j+1]='.';
                cnta--;
            }
            if(cntb>b&&c[i][j]=='^'){
                c[i][j]=c[i+1][j]='.';
                cntb--;
            }
        }
    }
    cout<<"YES"<<endl;
    rep(i,n){
        rep(j,m){
            cout<<c[i][j];
        }
        cout<<endl;
    }
}
signed main(){
    cin.tie(0);ios::sync_with_stdio(false);
    //int t;cin>>t;while(t--)
    solve();
    return 0;
}

Measured memory_bytes: 4620