#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define f first
#define s second
#define pii pair<ll, ll>
#define SZ(x) (int)(x).size()
#define ALL(x) (x).begin(), (x).end()
#define pb push_back
#define MX(a,b) a = max(a,b)
#define MN(a,b) a = min(a,b)
#define FOR(i,a,b) for (int i = a; i<b; ++i)
#define REP(i,n) FOR(i,0,n)
#define REP1(i,n) FOR(i,1,n+1)
#ifdef BALBIT
#define bug(...) cerr<<"#"<<__LINE__<<"- "<<#__VA_ARGS__<<": ", _do(__VA_ARGS__)
template<typename T> void _do(T && x) {cerr<<x<<endl;}
template<typename T, typename ...S> void _do(T && x, S && ...y) {cerr<<x<<", "; _do(y...);}
#else
#define bug(...)
#define endl '\n'
#endif // BALBIT
const int maxn = 1.5e5+5;
struct pt{
int x,y,z;
void in(){
cin>>x>>y>>z;
}
};
vector<array<int, 3> > v[3];
signed main(){
ios::sync_with_stdio(0), cin.tie(0);
bug(1,2);
int n; cin>>n;
REP(i,n) {
array<int, 3> a;
cin>>a[0]>>a[1]>>a[2];
REP(j,3) v[j].pb(a);
}
REP(j,3) {
sort(ALL(v[j]), [&](array<int, 3> x, array<int, 3> y){return x[j] < y[j];});
}
ll re = -1;
while (SZ(v[0]) && SZ(v[1]) && SZ(v[2])) {
bool bad = 0;
REP(j,3) {
REP(k,3) {
if (k !=j) {
if (v[j].back()[k] >= v[k].back()[k]) {
v[j].pop_back(); bad = 1; goto nope;
}
}
}
}
nope:;
if (!bad) {
re = 0;
REP(j,3) {
re += v[j].back()[j];
}
break;
}
}
cout<<re<<endl;
}
