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

template<typename T>
istream &operator >> (istream &istr, vector<T> &v){
    for(T &x: v) istr >> x;
    return istr;
}

template<typename T, typename U>
istream &operator >> (istream &istr, pair<T,U> &p){
    istr >> p.first >> p.second;
    return istr;
}

template<typename T>
ostream &operator << (ostream &ostr, vector<T> &v){
    if(!v.empty()){
        ostr << v.front();
        for(auto itr = ++v.begin(); itr != v.end(); itr++)
            // ostr << *itr;
            ostr << " " << *itr;
    }
    return ostr;
}

template<typename T, typename U>
ostream &operator << (ostream &ostr, pair<T,U> &p){
    // ostr << p.first << p.second;
    // ostr << p.first << ", " << p.second;
    ostr << "(" << p.first << ", " << p.second << ")";
    return ostr;
}

template<typename T>
ostream &operator << (ostream &ostr, vector<vector<T>> &vv){
    if(!vv.empty()){
        ostr << vv.front();
        for(auto itr = ++vv.begin(); itr != vv.end(); itr++)
            ostr << endl << *itr;
    }
    return ostr;
}

template<typename T, typename U>
ostream &operator << (ostream &ostr, vector<pair<T,U>> &vp){
    if(!vp.empty()){
        ostr << vp.front();
        for(auto itr = ++vp.begin(); itr != vp.end(); itr++)
            ostr << endl << *itr;
    }
    return ostr;
}

typedef long long ll;
typedef vector<ll> vll;
typedef vector<char> vc;
typedef vector<double> vd;
// vll v(n); v[i]=x;
typedef vector<vll> vvll;
typedef vector<vc> vvc;
typedef vector<vd> vvd;
// vvll v(m,vll(n)); v[i][j]=x;
typedef pair<ll,ll> pll;
typedef pair<double,double> pd;
typedef vector<pll> vpll;
typedef vector<pd> vpd;
// vpll v(n); v[i]=make_pair(x,y); v[i].first/second;
// v.front() : v[0]
// v.back()  : v[v.size()-1]

#define PI 3.1415926535897932
#define EPS 1e-12
#define INF ((ll)1e+12)
#define REP(i,n) for(ll i=0; i<(n); i++)
#define RREP(i,n) for(ll i=(n)-1; i>=0; i--)
#define FOR(i,a,b) for(ll i=(a); i<=(b); i++)
#define FORR(i,a,b) for(ll i=(b); i>=(a); i--)
#define fix(x) cout << fixed << setprecision(x)
#define dump(x) cout << #x << " = " << (x) << endl
#define all(x) (x).begin(),(x).end()

template<typename T> T sum(vector<T> &v){return accumulate(all(v), (T)0);}
template<typename T> inline void sort(vector<T> &v){sort(all(v));}
template<typename T> inline void rsort(vector<T> &v){sort(all(v), greater<T>());}
template<typename T> inline void chmin(T &a, T b){if(a>b) a=b;}
template<typename T> inline void chmax(T &a, T b){if(a<b) a=b;}

// n乗(繰り返し二乗法)
ll pow_mod(ll n, ll k, ll mod){
    ll ans = 1;
    for(; k>0; k>>=1){
        if(k&1) ans = (ans * n) % mod;
        n = n * n % mod;
    }
    return ans;
}

int main(){
    ll n, m, x, ans = INF;
    cin >> n >> m >> x;
    vll c(n);
    vvll a(n, vll(m));
    REP(i,n) cin >> c[i] >> a[i];

    ll lim = pow_mod(2, n, 10000);
    REP(i,lim){
        ll tmp = 0;
        vll b(m, 0);
        REP(j,n){
            if((i >> j) & 1){
                tmp += c[j];
                REP(k,m) b[k] += a[j][k];
            }
        }
        REP(k,m){
            if(b[k] < x) break;
            if(k == m-1) chmin(ans, tmp);
        };
    }
    if(ans < INF) cout << ans << endl;
    else cout << -1 << endl;
    return 0;
}


Measured memory_bytes: 3636