#include <bits/stdc++.h>
using namespace std;
int main() {
  long n, m, i, j;
  char x[2], y[2], t;
  cin >> n >> m;
  cin >> x[0];
  for (i = 2; i < n; i++) cin >> t;
  cin >> x[1] >> y[0];
  y[0] = (y[0] == '^') ? '>' : '<';
  for (j = 2; j < m; j++) cin >> t;
  cin >> y[1];
  y[1] = (y[1] == '^') ? '>' : '<';
  if (x[0] == y[0] && x[1] == y[1] && x[0] != x[1])
    cout << "YES";
  else
    cout << "NO";
}
