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#include<bits/stdc++.h>
#define VAR(i,n) __typeof(n) i = (n)
#define loop(i,j,s) for(int i=j;i<s;i++)
#define loopback(i,j,s) for(int i=j;i>=s;i--)
#define foreach(i,c) for(VAR(i,(c).begin());i!=(c).end();i++)
#define pln( x ) cout << x << "\n"
#define ps( x ) cout << x << " "
#define entr cout << "\n"
#define pcnt(i) __builtin_popcount(i)
#define ll long long
#define pb push_back
#define mp make_pair
#define ff first
#define ss second
#define SIZE(c) (c).size()
#define ALL(c) (c).begin(), (c).end()
using namespace std;
typedef vector<int> VI;
const int INFTY=20000000;
const int MAX=310;
const int MOD=10000000;

void coutTab(int* tab,int n){
	loop(i,0,n){
		cout<<tab[i]<<" ";
	}
	cout<<"\n";
}
//------------------------------------------
vector<VI > G(MAX);
int n;
int blk[MAX];
VI countLon(){
	vector<int>  l(n), p(n);
	loop(i,0,n){ l[i]=-1; p[i]=-1; } 
	int mxi=-1,mx=0;
	loopback(i,n-1,0){
		int res=0;
		if(blk[i]>0) continue;
		loop(j,0,G[i].size()){
			if(blk[G[i][j]]==0 && l[G[i][j]]>res){
				res = l[G[i][j]];
				p[i] = G[i][j];
			}
		}
		l[i]=res+1;
		if(l[i]>mx){
			mx=l[i];
			mxi=i;
		}
	}
	VI path;
	int c=mxi;
	while(c!=-1){
		path.pb(c);
		c=p[c];
	}
	return path;
}
int count(int k){
	VI lonP = countLon();
	if(k==0) return lonP.size();
	int mini = lonP.size();
	for(int v: lonP){
		blk[v]++;
		mini = min(mini,count(k-1));
		blk[v]--;
	}
	return mini;
}
int main(){
	ios_base::sync_with_stdio(0);
	int m,k;
	cin>>n>>m>>k;;
	int a,b;
	loop(i,0,m){
		cin>>a>>b;
		G[a-1].pb(b-1);
	}
	pln(count(k));
}