#include <bits/stdc++.h>
using namespace std;
int abs(int x) { return x < 0 ? -x : x; }
int n, a, b, c, x[5], y[5], X, Y, i, k;
long long T, now[5];
long long seq(int S, int L) { return 1ll * (S + S + L - 1) * L / 2ll; }
long long calc(int X, int Y, int x, int y) {
  if (x >= X && y >= Y) return seq(1, x + y - X - Y) + seq(1, 2 * n - x - y);
  if (x < X && y >= Y)
    return seq(X - x + 1, 2 * n - X - y) + seq(X - x, y - Y + 1);
  if (x >= X && y < Y)
    return seq(y - Y + 1, 2 * n - x - Y) + seq(Y - y, x - X + 1);
  if (x < X && y < Y) return seq(X + Y - x - y, 2 * n - X - Y + 1);
}
int main() {
  scanf("%d%I64d%d%d%d", &n, &T, &a, &b, &c);
  x[1] = a;
  y[1] = b;
  x[2] = a + c - 1;
  y[2] = b;
  x[3] = a;
  y[3] = b + c - 1;
  x[4] = a + c - 1;
  y[4] = b + c - 1;
  X = 1;
  Y = 1;
  now[1] = now[2] = now[3] = now[4] = 0;
  for (i = 1; i <= 4; i++)
    if (calc(1, 1, x[i], y[i]) - abs(x[i] - 1) - abs(y[i] - 1) > T)
      return puts("Impossible"), 0;
  for (k = 1; k <= 2 * n - 2; k++) {
    c = 0;
    if (X < n) {
      for (i = 1; i <= 4; i++)
        if (now[i] + calc(X + 1, Y, x[i], y[i]) > T) break;
      if (i == 5) c = 1;
    }
    putchar(c ? 'R' : 'U');
    if (c)
      X++;
    else
      Y++;
    for (i = 1; i <= 4; i++) now[i] += abs(x[i] - X) + abs(y[i] - Y);
  }
}
