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#include <bits/stdc++.h>

using namespace std;

typedef pair<int, int> pii;
#define fir first
#define sec second
typedef vector<int> vi;
#define pb push_back
#define ppb pop_back
#define empb emplace_back

#define N 320
#define M 400

int n, m, k, ans;
int dp[N];
int dout[N];
vi in[N];
//vi out[N];

void dfs(int i = 0, int c = 0, int res = 0)
{
    if (i == n) {
        ans = min(ans, res);
        return;
    }
    if (res >= ans) return;
    dp[i] = 0;
    if (c < k && dout[i] != 0) dfs(i+1, c+1, res);
    for (int j : in[i]) dp[i] = max(dp[i], dp[j]);
    dfs(i+1, c, max(res, ++dp[i]));
    if (c < k && dout[i] == 0) dfs(i+1, c+1, res);
}

/*void sfd(int i, int c = 0, int res = 0)
{
    if (i < 0) {
        ans = min(ans, res);
        return;
    }
    if (res >= ans) return;
    dp[i] = 0;
    if (c < k) sfd(i-1, c+1, res);
    for (int j : out[i]) dp[i] = max(dp[i], dp[j]);
    sfd(i-1, c, max(res, ++dp[i]));
}*/

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);

    cin >> n >> m >> k;
    ans = n;
    if (k == n) return cout << "0\n", 0;
    if (k == n-1) return cout << "1\n", 0;
    if (m == n*(n-1)/2) return cout << n-k << '\n', 0;
    for (int i = 0; i < m; ++i) {
        int x, y;
        cin >> x >> y;
        --x; --y;
        //out[x].pb(y);
        ++dout[x];
        in[y].pb(x);
    }
    for (int i = 0; i < n; ++i) {
        sort(in[i].begin(), in[i].end());
        //sort(out[i].begin(), out[i].end());
    }
    dfs();
    //sfd(n-1);
    cout << ans << '\n';

    return 0;
}