#include <bits/stdc++.h>
using namespace std;

int main() {
	//入力
	int N,M,K; cin >> N >> M >> K;
	assert(1<=N&&N<=20);
	assert(1<=M&&M<=20);
	assert(1<=K&&K<=1000);

	vector<vector<int>> a(N,vector<int>(M));
	for(int i = 0; i < N; ++i) {
		for(int j = 0; j < M; ++j) {
			cin >> a[i][j];
			assert(1 <= a[i][j] && a[i][j] <= 20);
		}
	}

	//ソート、差分計算、初期値
	int sum = 0;
	for(int i = 0; i < N; ++i) {
		sort(a[i].begin(),a[i].end());
		int ini = a[i][0];
		sum += ini;
		for(int j = 0; j < M; ++j) a[i][j] -= ini;
	}
	cout << max(K-sum,-1) << endl;

    return 0;
}