#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
vector<vector<ll>> memo(31, vector<ll>(31, -1));
ll f(int a, int b) {
	if (memo[a][b] != -1) return memo[a][b];
	if (a == 0) {
		return 1;
	}
	if (b == 0) {
		return 1;
	}
	ll va = f(a - 1, b);
	ll vb = f(a, b - 1);
	memo[a][b] = va + vb;
	return va + vb;
}
#ifdef _DEBUG
#define show(x)          \
	cerr << #x << " : "; \
	showVal(x)
template <typename T>
void showVal(const T &a) { cerr << a << endl; }
template <typename T>
void showVal(const vector<T> &a) {
	for (const T &v : a) cerr << v << " ";
	cerr << endl;
}
template <typename T>
void showVal(const vector<vector<T>> &a) {
	cerr << endl;
	for (const vector<T> &v : a) showVal(v);
}
#else
#define show(x)
#endif
int main() {
	ll k;
	int a, b;
	cin >> a >> b >> k;
	f(a, b);
	string ans;
	int sz = a + b;
	for (int i = 0; i < sz; i++) {
		if (a > 0 && f(a - 1, b) >= k) {
			ans += 'a';
			a--;
		} else {
			if (a > 0) k -= f(a - 1, b);
			b--;
			ans += 'b';
		}
		show(k);
	}
	cout << ans << endl;
	return 0;
}
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define FOR(i, a, b) for(int i = (int)a; i <= (int)b; i++)
#define DEC(i, a, b) for(int i = (int)a; i >= (int)b; i--)
typedef pair<int, int> pi;
typedef pair<pi, int> pii;
typedef pair<pi, pi> pipi;
#define f first
#define s second
typedef vector<int> vi;
typedef vector<pi> vpi;
typedef vector<pii> vpii;
#define pb push_back
#define pf push_front
#define all(v) v.begin(), v.end()
#define disc(v) sort(all(v)); v.resize(unique(all(v)) - v.begin());
#define INF (int) 1e9 + 100
#define LLINF (ll) 1e18
#define fastio ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define sandybridge __attribute__((optimize("Ofast"), target("arch=sandybridge")))
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());    //can be used by calling rng() or shuffle(A, A+n, rng)
inline ll rand(ll x, ll y) { ++y; return (rng() % (y-x)) + x; } //inclusivesss

int n, vis[105], coun;
ld x[105], y[105], r;

inline ld sqr(ld t) {
	return t*t;
}

void dfs(int node) {
	vis[node] = coun;
	FOR(i, 1, n) if (sqr(x[i] - x[node]) + sqr(y[i] - y[node]) < sqr(2*r) and vis[i] == -1) dfs(i);
}

bool check(ld g) {
	memset(vis, -1, sizeof vis);
	coun = 0;
	r = g;
	FOR(i, 1, n) if (100 - y[i] < 2*r and vis[i] == -1) ++coun, dfs(i);
	FOR(i, 1, n) if (y[i] + 100 < 2*r and vis[i] != -1) return 0;
	return 1;
}

int main() {
	fastio; cout << fixed << setprecision(4);
	cin >> n;
	FOR(i, 1, n) cin >> x[i] >> y[i];
	ld lower = 0, upper = 100.0001;
	while (upper - lower > (ld) 0.0001) {
		ld mid = (upper + lower)/2;
		if (check(mid)) lower = mid;
		else upper = mid;
	}
	cout << lower;
}
