#include <bits/stdc++.h>
using namespace std;
long long int fastpow(long long int tab, long long int us) {
  if (tab == 0) return 0;
  if (tab == 1) return 1;
  if (us == 0) return 1;
  if (us == 1) return tab % 1000000007;
  tab %= 1000000007;
  if (us % 2 == 1) return tab * fastpow(tab, us - 1) % 1000000007;
  long long int a = fastpow(tab, us / 2) % 1000000007;
  return a * a % 1000000007;
}
long long int t = 1, n, m;
char mat[52][52], ist[52][52];
vector<pair<long long int, long long int> > cev;
void rot(long long int x, long long int y) {
  if (mat[x][y] == 'U') {
    if (mat[x][y + 1] == 'L' and mat[x + 1][y + 1] == 'L') {
      rot(x, y + 1);
    } else if (mat[x][y + 1] == 'L' and mat[x + 1][y + 1] == 'U') {
      rot(x + 1, y + 1);
      rot(x, y + 1);
    }
    mat[x][y] = 'L';
    mat[x][y + 1] = 'R';
    mat[x + 1][y] = 'L';
    mat[x + 1][y + 1] = 'R';
    cev.push_back(make_pair(x + 1, y + 1));
  } else {
    if (mat[x + 1][y] == 'U' and mat[x + 1][y + 1] == 'U') {
      rot(x + 1, y);
    } else if (mat[x + 1][y] == 'U' and mat[x + 1][y + 1] == 'L') {
      rot(x + 1, y + 1);
      rot(x + 1, y);
    } else if (mat[x + 1][y] == 'R' and mat[x + 1][y + 1] == 'L') {
      rot(x + 1, y - 1);
      rot(x + 1, y + 1);
      rot(x + 1, y);
    } else if (mat[x + 1][y] == 'R' and mat[x + 1][y + 1] == 'U') {
      rot(x + 1, y - 1);
      rot(x + 1, y);
    }
    mat[x][y] = 'U';
    mat[x][y + 1] = 'U';
    mat[x + 1][y] = 'D';
    mat[x + 1][y + 1] = 'D';
    cev.push_back(make_pair(x + 1, y + 1));
  }
}
void solve() {
  long long int i, j, k;
  cin >> n >> m;
  for (i = 0; i < n; i++)
    for (j = 0; j < m; j++) cin >> mat[i][j];
  for (i = 0; i < n; i++)
    for (j = 0; j < m; j++) cin >> ist[i][j];
  for (i = 0; i < n - 1; i++) {
    for (j = 0; j < m - 1; j++) {
      if (mat[i][j] != ist[i][j]) rot(i, j);
    }
  }
  cout << cev.size() << endl;
  for (i = 0; i < cev.size(); i++) {
    cout << cev[i].first << " " << cev[i].second << endl;
  }
  return;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  while (t--) solve();
  return 0;
}
