#include <cstdio>#include <algorithm>#include <cstring>#include <bitset>using namespace std;const int MAX = 110;bitset<MAX> ans[MAX];bitset<MAX> dif;int u[MAX*MAX];int v[MAX*MAX];int deg[MAX];int u1,u2,v1,v2;struct p{ int ind,dunum; bool operator < (const p & rhs) const{ return dunum > rhs.dunum; }} du[MAX];int n;bool judge(){ sort(du+1,du+1+n); for(int k = 1; k <= n; ++k){ sort(du+k+1,du+n+1); if(du[k].dunum > n - k) return false; for(int j = 1; j <= du[k].dunum;++j){ if(--du[k+j].dunum < 0) return false; ans[du[k].ind][du[k+j].ind] = ans[du[k+j].ind][du[k].ind]=1; } } return true;}bool found(){ for(int i = 1; i <= n; ++i){ for(int j = i + 1; j <= n; ++j){ v1 = v2 = 0; dif = ans[i]&(~ans[j]); for(int k = 1; k <=n; ++k) if(dif[k] && k != i) v1 = k; dif = (~ans[i]) & ans[j]; for(int k = 1; k <= n; ++k){ if(dif[k]&& k != j) v2 = k; } if (v1 && v2){ u1 = i, u2 = j; return true; } } } return false;}void print(){ int sum = 0; for(int i = 1; i <= n; ++i) for(int j = 1; j < i; ++j) if(ans[i][j]) u[sum] = i,v[sum++] = j; printf("%d %dn",n,sum); for(int i = 0; i < sum; ++i) printf("%d%c",u[i], i == sum - 1?'n':' '); for(int i = 0; i < sum; ++i) printf("%d%c",v[i], i == sum - 1?'n':' '); if(sum == 0) printf("nn");}int main(void){ while(scanf("%d",&n) != EOF){ for(int i = 1; i <= n; ++i){ ans[i].reset(); ans[i][i] = 1; scanf("%d",&du[i].dunum); du[i].ind = i; deg[i] = du[i].dunum; } if(!judge()) puts("IMPOSSIBLE"); else { if(found()){ puts("MULTIPLE"); print(); ans[u1][v1] = ans[v1][u1] = 0; ans[u1][v2] = ans[v2][u1] = 1; ans[u2][v2] = ans[v2][u2] = 0; ans[u2][v1] = ans[v1][u2] = 1; print(); } else{ puts("UNIQUE"); print(); } } } return 0;}
