#include <bits/stdc++.h>
using namespace std;
long long n, T, a, b, c;
int x[4], y[4];
long long cost[4];
string ans;
long long f(long long x, long long y) { return (x + y) * (abs(y - x) + 1) / 2; }
long long Cal(int X, int Y, int x, int y) {
  if (X <= x && Y <= y) return f(0, x + y - X - Y) + f(0, n + n - x - y);
  if (X >= x && Y >= y) return f(X + Y - x - y, n + n - x - y);
  if (X <= x && Y >= y)
    return f(x + Y - X - y, Y - y + 1) + f(Y - y, n + n - x - y);
  return f(X + y - x - Y, X - x + 1) + f(X - x, n + n - x - y);
}
long long rm[4];
bool ok(int X, int Y) {
  for (int i = 0; i < 4; ++i)
    if ((rm[i] = T - cost[i] - Cal(X, Y, x[i], y[i])) < 0) return false;
  if (X < a + c && Y < b + c)
    return ((rm[1] >> 1) + (rm[2] >> 1)) >=
           (long long)(a + c - max((int)a, X)) * (b + c - max((int)b, Y));
  return true;
}
int main() {
  cin >> n >> T >> a >> b >> c;
  --c;
  x[1] = x[0] = a, y[2] = y[0] = b;
  x[2] = x[3] = a + c, y[1] = y[3] = b + c;
  int X = 1, Y = 1;
  for (int i = 0; i < 4; ++i)
    if (Cal(X, Y, x[i], y[i]) - abs(x[i] - X) - abs(y[i] - Y) > T)
      return puts("Impossible"), 0;
  while (X != n || Y != n) {
    if (X < n && ok(X + 1, Y))
      ++X, ans += 'R';
    else
      ++Y, ans += 'U';
    for (int i = 0; i < 4; ++i) cost[i] += abs(x[i] - X) + abs(y[i] - Y);
  }
  cout << ans << endl;
  return 0;
}
