#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1010;
int dp[MAXN][MAXN];
string par[MAXN][MAXN], t, s;
void pp(int i, int j) {
  if (i == 0 && j == 0) return;
  if (par[i][j] == "INSERT") {
    cout << "INSERT"
         << " " << i + 1 << " " << t[j - 1] << endl;
    pp(i, j - 1);
  }
  if (par[i][j] == "REPLACE") {
    cout << "REPLACE"
         << " " << i << " " << t[j - 1] << endl;
    pp(i - 1, j - 1);
  }
  if (par[i][j] == "DELETE") {
    cout << "DELETE"
         << " " << i << endl;
    pp(i - 1, j);
  }
  if (par[i][j] == "") pp(i - 1, j - 1);
}
int main() {
  cin >> s >> t;
  for (int i = 0; i <= max(s.size(), t.size()); i++) {
    dp[i][0] = i;
    par[i][0] = "DELETE";
    dp[0][i] = i;
    par[0][i] = "INSERT";
  }
  int n = s.size(), m = t.size();
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= m; j++) {
      if (s[i - 1] == t[j - 1])
        dp[i][j] = dp[i - 1][j - 1];
      else {
        if (min(dp[i - 1][j - 1] + 1,
                min(dp[i - 1][j] + 1, dp[i][j - 1] + 1)) ==
            dp[i - 1][j - 1] + 1) {
          par[i][j] = "REPLACE";
          dp[i][j] = dp[i - 1][j - 1] + 1;
        }
        if (min(dp[i - 1][j - 1] + 1,
                min(dp[i - 1][j] + 1, dp[i][j - 1] + 1)) == dp[i - 1][j] + 1) {
          par[i][j] = "DELETE";
          dp[i][j] = dp[i - 1][j] + 1;
        }
        if (min(dp[i - 1][j - 1] + 1,
                min(dp[i - 1][j] + 1, dp[i][j - 1] + 1)) == dp[i][j - 1] + 1) {
          par[i][j] = "INSERT";
          dp[i][j] = dp[i][j - 1] + 1;
        }
      }
    }
  }
  cout << dp[n][m] << endl;
  pp(n, m);
  return 0;
}
