#include <bits/stdc++.h>
using namespace std;
int n, m;
char st[2][55][55];
bool swp;
vector<pair<int, int> > p[2];
void res(int r, int c, bool dir, int v) {
  if (!dir) {
    if (st[v][r][c] == 'L') return;
    res(r, c + 1, true, v);
    p[v].push_back({r, c});
    st[v][r][c] = st[v][r + 1][c] = 'L';
    st[v][r][c + 1] = st[v][r + 1][c + 1] = 'R';
  } else {
    if (st[v][r][c] == 'U') return;
    res(r + 1, c, false, v);
    p[v].push_back({r, c});
    st[v][r][c] = st[v][r][c + 1] = 'U';
    st[v][r + 1][c] = st[v][r + 1][c + 1] = 'D';
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cin >> n >> m;
  if (m % 2) {
    swp = true;
  }
  for (int i = 0; i < (signed)(n); i++) {
    for (int j = 0; j < (signed)(m); j++) {
      char c;
      cin >> c;
      if (swp) {
        if (c == 'U')
          c = 'L';
        else if (c == 'L')
          c = 'U';
        else if (c == 'D')
          c = 'R';
        else
          c = 'D';
        st[0][j][i] = c;
      } else {
        st[0][i][j] = c;
      }
    }
  }
  for (int i = 0; i < (signed)(n); i++) {
    for (int j = 0; j < (signed)(m); j++) {
      char c;
      cin >> c;
      if (swp) {
        if (c == 'U')
          c = 'L';
        else if (c == 'L')
          c = 'U';
        else if (c == 'D')
          c = 'R';
        else
          c = 'D';
        st[1][j][i] = c;
      } else {
        st[1][i][j] = c;
      }
    }
  }
  if (swp) swap(n, m);
  for (int i = 0; i < (signed)(n); i++) {
    for (int j = 0; j < m; j += 2) {
      res(i, j, false, 0);
      res(i, j, false, 1);
    }
  }
  cout << p[0].size() + p[1].size() << "\n";
  for (int i = 0; i < (signed)(p[0].size()); i++) {
    if (swp) {
      cout << p[0][i].second + 1 << " " << p[0][i].first + 1 << "\n";
    } else {
      cout << p[0][i].first + 1 << " " << p[0][i].second + 1 << "\n";
    }
  }
  for (int i = (p[1].size() - 1); i >= 0; i--) {
    if (swp) {
      cout << p[1][i].second + 1 << " " << p[1][i].first + 1 << "\n";
    } else {
      cout << p[1][i].first + 1 << " " << p[1][i].second + 1 << "\n";
    }
  }
  return 0;
}
