#include <bits/stdc++.h>
 
using namespace std;
 
#define lli long long int
#define REP(i,s,n) for(int i=s;i<n;i++)
#define MOD 1000000007
#define NUM 2520
#define INF (1LL<<50)
#define DEBUG 0
#define mp(a,b) make_pair(a,b)
#define SORT(V) sort(V.begin(),V.end())

signed main(){
 
	lli n,m,k;
	cin>>n>>m>>k;

	lli data[12][12];

	REP(i,0,n)REP(j,0,m)cin>>data[i][j];

	/*もっとも小さい10個を選んでいく*/

	vector<lli> index(n);
	REP(i,0,n)index[i]=1;

	lli sum = 0;
	REP(i,0,n)sum+=data[i][0];

	if(sum>k){
		cout<<-1<<endl;
		return 0;
	}
	lli ans = k-sum;
	if(ans==0){
		cout<<0<<endl;
		return 0;
	}

	/*ここから細かく見ていくために,一番増える幅が小さいものを選んでいく*/
	while(1){
		bool breakF = true;

		lli diff=INF;
		lli diffIndex=-1;
		REP(i,0,n){
			if(index[i]>=m)continue;
			if(diff>data[i][index[i]]-data[i][index[i]-1]){
				diff = data[i][index[i]]-data[i][index[i]-1];
				diffIndex=i;
				breakF = false;
			}
		}
		if(breakF)break;

		sum += diff;
		if(k-sum<0)break;
		ans = min(ans,k-sum);
		index[diffIndex]++;
	}
	cout<<ans<<endl;

	return 0;
}