#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define fi first
#define se second
#define pii pair<int, int>
using namespace std;
const int maxN = 150001;
int n;
int x[maxN], y[maxN], z[maxN];
void Input()
{
cin >> n;
for(int i = 1; i <= n; i++)
cin >> x[i] >> y[i] >> z[i];
}
int idx[maxN], idy[maxN], idz[maxN];
bool flag[maxN];
bool ss1(int a, int b)
{
return x[a] < x[b];
}
bool ss2(int a, int b)
{
return y[a] < y[b];
}
bool ss3(int a, int b)
{
return z[a] < z[b];
}
void Solve()
{
for(int i = 1; i <= n; i++)
{
idx[i] = i;
idy[i] = i;
idz[i] = i;
}
sort(idx + 1, idx + 1 + n, ss1);
sort(idy + 1, idy + 1 + n, ss2);
sort(idz + 1, idz + 1 + n, ss3);
int resx = n, resy = n, resz = n;
while(resx != 0 && resy != 0 && resz != 0)
{
int tmpx = x[idx[resx]], tmpy = y[idy[resy]], tmpz = z[idz[resz]];
int xx = (y[idx[resx]] == tmpy) + (z[idx[resx]] == tmpz);
int yy = (z[idy[resy]] == tmpz) + (x[idy[resy]] == tmpx);
int zz = (x[idz[resz]] == tmpx) + (y[idz[resz]] == tmpy);
if(xx == 0 && yy == 0 && zz == 0)
{
cout << tmpx + tmpy + tmpz;
return;
}
if(xx > 0)
{
flag[idx[resx]] = true;
goto hi;
}
if(yy > 0)
{
flag[idy[resy]] = true;
goto hi;
}
if(zz > 0)
{
flag[idz[resz]] = true;
goto hi;
}
hi:
while(resx != 0 && flag[idx[resx]])
resx--;
while(resy != 0 && flag[idy[resy]])
resy--;
while(resz != 0 && flag[idz[resz]])
resz--;
}
cout << -1;
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
Input();
Solve();
}
