#include <bits/stdc++.h>
using namespace std;
#ifdef DEBUG
#define dbg(...) printf(__VA_ARGS__);
#define getchar_unlocked getchar
#else
#define dbg(...)
#endif
#define sf scanf
#define pf printf
#define fi first
#define se second
#define pb push_back
#define sz(x) (int)x.size()
#define mnto(x,y) x=min(x,(__typeof__(x))y)
#define mxto(x,y) x=max(x,(__typeof__(x))y)
#define INF 1023456789
#define LINF 1023456789123456789
#define all(x) x.begin(), x.end()
#define disc(x) sort(all(x));x.resize(unique(all(x))-x.begin());
typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
typedef tuple<int, int, int> iii;
typedef tuple<int, int, int, int> iiii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<pll> vll;
mt19937 rng(time(0));
#define mod 1000000007
inline int add(int a,int b){
int r=a+b;
while(r>=mod)r-=mod;
while(r<0)r+=mod;
return r;
}
inline int mult(int a,int b){
return (int)(((ll)(a*b))%mod);
}
inline int rd(){
int x=0;
char ch=getchar_unlocked();
while(!(ch&16))ch=getchar();//keep reading while current character is whitespace
while(ch&16){//this will break when ‘\n’ or ‘ ‘ is encountered
x=(x<<3)+(x<<1)+(ch&15);
ch=getchar_unlocked();
}
return x;
}
#define maxn 150005
set<ii> sx,sy,sz;
int n,x[maxn],y[maxn],z[maxn];
void del(int i){
sx.erase(sx.find({x[i],i}));
sy.erase(sy.find({y[i],i}));
sz.erase(sz.find({z[i],i}));
}
int main(){
sf("%d",&n);
for(int i=0;i<n;++i){
sf("%d%d%d",&x[i],&y[i],&z[i]);
sx.insert({x[i],i});
sy.insert({y[i],i});
sz.insert({z[i],i});
}
while(true){
if(sx.empty()||sy.empty()||sz.empty())pf("-1\n"),exit(0);
int a=(*--sx.end()).se,b=(*--sy.end()).se,c=(*--sz.end()).se;
if(y[a]>=y[b]||z[a]>=z[c])del(a);
else if(x[b]>=x[a]||z[b]>=z[c])del(b);
else if(x[c]>=x[a]||y[c]>=y[b])del(c);
else pf("%d\n",x[a]+y[b]+z[c]),exit(0);
}
}
