#include <stdio.h>
#define N 150000
unsigned int X = 12345;
int rand_() {
return (X *= 3) >> 1;
}
int *ww;
void sort(int *ii, int l, int r) {
while (l < r) {
int i = l, j = l, k = r, i_ = ii[l + rand_() % (r - l)], tmp;
while (j < k)
if (ww[ii[j]] == ww[i_])
j++;
else if (ww[ii[j]] < ww[i_]) {
tmp = ii[i], ii[i] = ii[j], ii[j] = tmp;
i++, j++;
} else {
k--;
tmp = ii[j], ii[j] = ii[k], ii[k] = tmp;
}
sort(ii, l, i);
l = k;
}
}
int main() {
static int xx[N], yy[N], zz[N], ii[N], jj[N], kk[N];
static char deleted[N];
int n, i, i_, j, j_, k, k_;
scanf("%d", &n);
for (i = 0; i < n; i++)
scanf("%d%d%d", &xx[i], &yy[i], &zz[i]);
for (i = 0; i < n; i++)
ii[i] = jj[i] = kk[i] = i;
ww = xx, sort(ii, 0, n);
ww = yy, sort(jj, 0, n);
ww = zz, sort(kk, 0, n);
i = n - 1, j = n - 1, k = n - 1;
while (1) {
i_ = j_ = k_ = -1;
while (i >= 0 && deleted[i_ = ii[i]])
i--;
while (j >= 0 && deleted[j_ = jj[j]])
j--;
while (k >= 0 && deleted[k_ = kk[k]])
k--;
if (i < 0) {
printf("-1\n");
return 0;
}
if (yy[i_] >= yy[j_] || zz[i_] >= zz[k_])
deleted[i_] = 1;
else if (zz[j_] >= zz[k_] || xx[j_] >= xx[i_])
deleted[j_] = 1;
else if (xx[k_] >= xx[i_] || yy[k_] >= yy[j_])
deleted[k_] = 1;
else {
printf("%d\n", xx[i_] + yy[j_] + zz[k_]);
return 0;
}
}
return 0;
}
