#include <bits/stdc++.h>   using namespace std;   const int maxn = 1e6;   int q[maxn], fin, razbeg, jump, n;   pair<int, int> ans[maxn];   int sz = 0;   int main() {     cin >> n >> fin >> razbeg >> jump;     for (int i = 0; i < n; i++) cin >> q[i];     q[n] = 0;     q[n + 1] = fin;     n += 2;     sort(q, q + n);     int i = 0, now = 0;     while (i < n - 1)       if (i == n - 2) {         if (fin - now > 0) ans[sz] = make_pair(0, fin - now), sz++;         break;       } else if (q[i + 1] - 1 - now < razbeg) {         cout <<  IMPOSSIBLE ;         return 0;       } else {         if (q[i + 1] - 1 - now > 0)           ans[sz] = make_pair(0, q[i + 1] - 1 - now), sz++;         now = q[i + 1] - 1;         while (1) {           i++;           if (q[i] + 1 - now > jump) {             cout <<  IMPOSSIBLE ;             return 0;           }           if (i == n - 2) {             ans[sz] = make_pair(1, q[i] + 1 - now), sz++, now = q[i] + 1;             break;           } else if (q[i + 1] - 1 - q[i] - 1 >= razbeg) {             ans[sz] = make_pair(1, q[i] + 1 - now), sz++, now = q[i] + 1;             break;           }         }       }     for (int i = 0; i < sz; i++)       if (ans[i].first == 0)         cout <<  RUN   << ans[i].second <<   n ;       else         cout <<  JUMP   << ans[i].second <<   n ;   }   