#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <string>
#include <cstdlib>
#include <cstdio>
#include <cassert>
#include <cstring>
#include <cmath>
#include <ctime>
#include <climits>
#include <vector>
#include <queue>
#include <stack>
#include <set>
#include <bitset>
#include <map>
#include <utility>
#include <algorithm>
#include <numeric>
#include <functional>

#define forn(i, n) for (int i = 0; i < int(n); i++)
#define forl(i, n) for (int i = 1; i <= int(n); i++)
#define ford(i, n) for (int i = int(n) - 1; i >= 0; i--)
#define fore(i, l, r) for(int i = int(l); i <= int(r); i++)
#define all(a) (a).begin(), (a).end()
#define sz(a) int((a).size())
#define pb(a) push_back(a)
#define mp(x, y) make_pair((x), (y))
#define ft first
#define sc second
#define x first
#define y second

using namespace std;

template<typename X> inline X abs(const X& a) { return a < 0 ? -a : a; }
template<typename X> inline X sqr(const X& a) { return a * a; }

typedef long long li;
typedef long double ld;
typedef pair<int, int> pt;

const int INF = int(1e9);
const li INF64 = li(1e18);
const ld EPS = 1e-9;

const int N = 3000 + 3;

int n, m, k;
vector<int> g[N];

inline bool read()
{
    if (scanf("%d%d%d", &n, &m, &k) != 3) return false;

    forn(i, m)
    {
        int x, y;
        assert(scanf("%d%d", &x, &y) == 2);
        x--, y--;
        g[x].pb(y), g[y].pb(x);
    }

    return true;
}

int ansVal;
int used[N];
int perm[N];

int CNT = 200 * 1000 * 1000;

void solve(int idx, int curVal)
{
    if (--CNT < 0) return;
    if (curVal > k) return;
    if (curVal >= ansVal) return;

    if (idx == n) return void(ansVal = curVal);

    int v = perm[idx];

    if (used[v]) return solve(idx + 1, curVal);

    if (sz(g[v]) <= k)
    {
        int nextVal = curVal;
        forn(j, sz(g[v]))
        {
            nextVal += !used[g[v][j]];
            used[g[v][j]]++;
        }

        solve(idx + 1, nextVal);

        forn(j, sz(g[v]))
            used[g[v][j]]--;
    }

    used[v]++;
    solve(idx + 1, curVal + 1);
    used[v]--;
}

inline bool cmp(int i, int j) { return sz(g[i]) > sz(g[j]); }

inline void solve()
{
    forn(i, n) perm[i] = i;
    sort(perm, perm + n, cmp);
    //reverse(perm, perm + n);
    //random_shuffle(perm, perm + n);

    ansVal = k + 1;
    solve(0, 0);
    if (ansVal == k + 1) puts("Impossible");
    else cout << ansVal << endl;
}

int main()
{
#ifdef SU2_PROJ
    assert(freopen("input.txt", "rt", stdin));
    //assert(freopen("output.txt", "wt", stdout));
#endif

    assert(read());
    solve();

    return 0;
}