#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef double db;
typedef string str;
// change ld to db if neccesary
typedef pair<int,int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pld;
typedef set<int> si;
typedef set<ll> sl;
typedef set<ld> sld;
typedef set<str> ss;
typedef set<pi> spi;
typedef set<pl> spl;
typedef set<pld> spld;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<ld> vld;
typedef vector<str> vs;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<si> vsi;
typedef vector<sl> vsl;
typedef vector<pld> vpld;
#define mp make_pair
#define f first
#define s second
#define sz(x) (int)(x).size()
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend()
#define rsz resize
#define ins insert
#define ft front()
#define bk back()
#define pf push_front
#define pb push_back
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound
#define forr(i,a,b) for (int i = (a); i < (b); i++)
#define ford(i,a,b) for (int i = (a)-1; i >= (b); i--)
#define trav(a,x) for (auto& a: x)
template<class T> bool ckmin(T& a, const T& b) { return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }
int pct(int x) { return __builtin_popcount(x); }
int bits(int x) { return 31-__builtin_clz(x); } // floor(log2(x))
int fstTrue(function<bool(int)> f, int lo, int hi) {
hi ++; assert(lo <= hi); // assuming f is increasing
while (lo < hi) { // find first index such that f is true
int mid = (lo+hi)/2;
f(mid) ? hi = mid : lo = mid+1;
}
return lo;
}
const ll MOD = 1e9+7;
const int dx[8] = {1, 0, -1, 0, 1, 1, -1, -1}, dy[8] = {0, 1, 0, -1, -1, 1, -1, 1};
int gcd(int a,int b){return b?gcd(b,a%b):a;}
ll binpow(ll a,ll b){ll res=1;while(b){if(b&1)res=(res*a)%MOD;a=(a*a)%MOD;b>>=1;}return res;}
ll modInv(ll a){return binpow(a, MOD-2);}
bool sortcol(const vl& v1, const vl& v2) {return v1[1] < v2[1];}
bool sortpair(const pi& p1, const pi& p2) {return p1.f < p2.f;}
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count());
uniform_int_distribution<long long unsigned> distribution(0,10);
void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}
// void __print(mi x) {cerr << x;}
template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifndef ONLINE_JUDGE
#define dbg(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define dbg(x...)
#endif
const int mxN = 2e5+5;
int n, ans[105];
array<int,3> curr;
void solve() {
cin >> n;
if ((n*(n+1)/2) % 3) cout << "IMPOSSIBLE\n";
else {
int mid = (n*(n+1)/2)/3;
// ford(i,n+1,1) {
// if (curr[2] + i <= mid+1) {
// curr[2] += i;
// ans[i] = 3;
// } else if (curr[1] + i <= mid) {
// curr[1] += i;
// ans[i] = 2;
// } else {
// curr[0] += i;
// ans[i] = 1;
// }
// }
// if (curr[0]+1 == curr[1] && curr[1]+1 == curr[2]) {
// forr(i,1,n+1) cout << ans[i] << " \n"[i==n];
// } else cout << "IMPOSSIBLE\n";
// assert(curr[0]+1 == curr[1] && curr[1]+1 == curr[2]);
// forr(i,1,n+1) cout << ans[i] << " \n"[i==n];
int one = 0;
ford(i,n+1,1) {
if (curr[2] + i <= mid) {
curr[2] += i;
ans[i] = 3;
if (i == 1) one = 3;
} else if (curr[1] + i <= mid) {
curr[1] += i;
ans[i] = 2;
if (i == 1) one = 2;
} else {
curr[0] += i;
ans[i] = 1;
if (i == 1) one = 1;
}
}
if (n > 3) assert(curr[0] == curr[1] && curr[1] == curr[2]);
}
}
int main() {
cin.tie(0)->sync_with_stdio(0);
// freopen(".in", "r", stdin);
// freopen(".out", "w", stdout);
int tc = 1;
// cin >> tc;
while (tc--) solve();
}