#include <cstdio>
#include <cctype>

template <typename T> T read() {
  T res = 0, f = 1;
  char ch = getchar();
  for (; !isdigit(ch); ch = getchar()) if (ch == '-') f = -1;
  for (; isdigit(ch); ch = getchar()) res = (res << 3) + (res << 1) + (ch ^ 48);
  return res * f;
}

#include <cmath>
const int MAXN = 1e6 + 10;

int n;
int idx[MAXN];

int main() {
  #ifdef LOCAL
    freopen("!input.in", "r", stdin);
    freopen("!output.out", "w", stdout);
  #else
    freopen("kmpp.in", "r", stdin);
    freopen("kmpp.out", "w", stdout);
  #endif
  n = read<int>();
  for (int i = 1; i <= n; ++i) {
    idx[i] = read<int>();
  }
  puts("Impossible");
  return 0;
}