#include <bits/stdc++.h>
using namespace std;
int n, m, s, d;
int main() {
  cin >> n >> m >> s >> d;
  vector<int> a(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  sort(a.begin(), a.end());
  if (s >= a[0]) {
    cout << "IMPOSSIBLE";
    return 0;
  }
  vector<pair<int, int> > kek;
  for (int i = 0; i < n; i++) {
    if (kek.empty()) {
      kek.push_back({a[i], a[i]});
    } else if (a[i] - kek.back().second - 2 >= s) {
      kek.push_back({a[i], a[i]});
    } else {
      kek.back().second = a[i];
    }
  }
  for (auto pii : kek) {
    if (pii.second - pii.first + 2 > d) {
      cout << "IMPOSSIBLE";
      return 0;
    }
  }
  int pos = 0;
  for (auto pii : kek) {
    cout << "RUN " << pii.first - pos - 1 << "\n";
    cout << "JUMP " << pii.second - pii.first + 2 << "\n";
    pos = pii.second + 1;
  }
  if (pos != m) {
    cout << "RUN " << m - pos;
  }
  return 0;
}
