macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        let mut next = || { iter.next().unwrap() };
        input_inner!{next, $($r)*}
    };
    ($($r:tt)*) => {
        let stdin = std::io::stdin();
        let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));
        let mut next = move || -> String {
            bytes
                .by_ref()
                .map(|r| r.unwrap() as char)
                .skip_while(|c| c.is_whitespace())
                .take_while(|c| !c.is_whitespace())
                .collect()
        };
        input_inner!{next, $($r)*}
    };
}

macro_rules! input_inner {
    ($next:expr) => {};
    ($next:expr, ) => {};

    ($next:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($next, $t);
        input_inner!{$next $($r)*}
    };

    ($next:expr, mut $var:ident : $t:tt $($r:tt)*) => {
        let mut $var = read_value!($next, $t);
        input_inner!{$next $($r)*}
    };
}

macro_rules! read_value {
    ($next:expr, ( $($t:tt),* )) => {
        ( $(read_value!($next, $t)),* )
    };

    ($next:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
    };

    ($next:expr, [ $t:tt ]) => {
        {
            let len = read_value!($next, usize);
            (0..len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
        }
    };

    ($next:expr, chars) => {
        read_value!($next, String).chars().collect::<Vec<char>>()
    };

    ($next:expr, usize1) => {
        read_value!($next, usize) - 1
    };

    ($next:expr, $t:ty) => {
        $next().parse::<$t>().expect("Parse error")
    };
}

#[allow(unused_imports)]
use std::cmp::{min, max};

fn main() {
    input!{
        h: usize,
        w: usize,
        mut a: usize,
        mut b: usize
    }
    let mut ans = vec![vec!['.'; w]; h];
    let mut f = false;
    if h * w % 2 == 1 {
        let mut i = 0;
        let mut j = w - 1;
        while i < h - 1 && b > 0 {
            ans[i][j] = '^';
            ans[i + 1][j] = 'v';
            i += 2;
            b -= 1;
        }
        i = h - 1;
        j = 1;
        while j < w && a > 0 {
            ans[i][j] = '<';
            ans[i][j + 1] = '>';
            j += 2;
            a -= 1;
        }
        if a * b % 2 == 1 {
            f = true;
            ans[h - 3][0] = '<';
            ans[h - 3][1] = '>';
            a -= 1;
            ans[h - 2][0] = '^';
            ans[h - 1][0] = 'v';
            b -= 1;
        }
    } else if h % 2 == 1 {
        for j in 0..w / 2 {
            if a == 0 {
                break;
            }
            ans[h - 1][2 * j] = '<';
            ans[h - 1][2 * j + 1] = '>';
            a -= 1;
        }
    } else if w % 2 == 1 {
        for i in 0..h / 2 {
            if b == 0 {
                break;
            }
            ans[2 * i][w - 1] = '^';
            ans[2 * i + 1][w - 1] = 'v';
            b -= 1;
        }
    }
    for i in 0..h / 2 {
        for j in 0..w / 2 {
            if f && 2 * i + 3 == h && j == 0 {
                continue;
            }
            if a >= 2 {
                ans[2 * i][2 * j] = '<';
                ans[2 * i][2 * j + 1] = '>';
                ans[2 * i + 1][2 * j] = '<';
                ans[2 * i + 1][2 * j + 1] = '>';
                a -= 2;
            } else if a == 1 {
                ans[2 * i][2 * j] = '<';
                ans[2 * i][2 * j + 1] = '>';
                a -= 1;
            } else if b >= 2 {
                ans[2 * i][2 * j] = '^';
                ans[2 * i + 1][2 * j] = 'v';
                ans[2 * i][2 * j + 1] = '^';
                ans[2 * i + 1][2 * j + 1] = 'v';
                b -= 2;
            } else if b == 1 {
                ans[2 * i][2 * j] = '^';
                ans[2 * i + 1][2 * j] = 'v';
                b -= 1;
                break;
            }
        }
    }
    if a > 0 || b > 0 {
        println!("NO");
        return;
    }
    println!("YES");
    for l in &ans {
        println!("{}", l.iter().cloned().collect::<String>());
    }
}


Measured memory_bytes: 9340