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#include <bits/stdc++.h>
using namespace std;
#define PII pair<int, int>
#define VI vector<int>
#define VPII vector<PII>
#define LL long long
#define LD long double
#define f first
#define s second
#define MP make_pair
#define PB push_back
#define ALL(c) (c).begin(), (c).end()
#define SIZ(c) (int)(c).size()
#define REP(i, n) for(int i = 0; i < (int)(n); ++i)
#define FOR(i, b, e) for(int i = (b); i <= (int)(e); ++i)
#define FORD(i, b, e) for(int i = (b); i >= (int)(e); --i)

#define Sim template<class n
Sim, class s> ostream & operator << (ostream &p, pair<n, s> x)
{return p << "<" << x.f << ", " << x.s << ">";}
Sim> auto operator << (ostream &p, n y) -> 
typename enable_if<!is_same<n, string>::value, decltype(y.begin(), p)>::type 
{int o = 0; p << "{"; for(auto c: y) {if(o++) p << ", "; p << c;} return p << "}";}
void dor() {cerr << endl;}
Sim, class...s> void dor(n p, s...y) {cerr << p << " "; dor(y...);}
Sim, class s> void mini(n &p, s y) {if(p>y) p = y;}
Sim, class s> void maxi(n &p, s y) {if(p<y) p = y;}
#ifdef DEB
#define debug(...) dor(__FUNCTION__, ":", __LINE__, ": ", __VA_ARGS__)
#else
#define debug(...)
#endif 

#define I(x) #x " = ", (x), " "
#define A(a, i) #a "[" #i " = ", i, "] = ", a[i], " "
const int MXN = 303;
VI V[MXN];
int res[MXN];
int nxt[MXN];
bool removed[MXN];

VI calc_longest(int n)
    {
    FOR(i, 1, n)
        {
        res[i] = 0;
        nxt[i] = 0;
        }

    FORD(x, n, 1)
        {
        if(removed[x])
            continue;

        for(auto i : V[x])
            {
            if(res[x] < res[i])
                {
                res[x] = res[i];
                nxt[x] = i;
                }
            }
        res[x]++;
        }

    int idx = 1;
    FOR(i, 1, n)
        if(res[idx] < res[i])
           idx = i;
 
    VI result;
    int siz = res[idx];
    REP(i, siz)
        {
        result.PB(idx);
        idx = nxt[idx];
        }

    return result;
    }

map<VI, int> memo;
int solve(int n, int k)
    {
    if(k == 0)return calc_longest(n).size();

    // check if calculeted prevously
    VI rem; 
    FOR(i, 1, n) 
        if(removed[i]) rem.PB(i); 
    if(memo.count(rem))return memo[rem];
    //

    VI candidates = calc_longest(n);

    int res = candidates.size();
    for(auto i : candidates)
        {
        removed[i] = 1;
        int r = solve(n, k-1);
        mini(res, r);
        removed[i] = 0;
        }
    return memo[rem] = res;
    }

int main()
    {
    int n, m, k;
    cin >> n >> m >> k;
    REP(i, m)
        {
        int a, b;
        cin >> a >> b;
        V[a].PB(b);
        }
    cout << solve(n, k) << endl;
    }