#include <bits/stdc++.h>
using namespace std;
void setup()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
}
struct SEGMENT_TREE
{
int mx[1200000], mn[1200000];
inline SEGMENT_TREE()
{
fill_n(mx, 1200000, -1);
fill_n(mn, 1200000, 1e9);
}
inline void Update(int ind, int l, int r, int x, int v)
{
if (r < x || x < l)
{
return;
}
if (l == r)
{
mx[ind] = max(mx[ind], v);
mn[ind] = (mn[ind] == -1 ? -1 : min(mn[ind], v));
return;
}
int m = (l + r) >> 1;
Update(ind << 1, l, m, x, v);
Update(ind << 1 | 1, m + 1, r, x, v);
mx[ind] = max(mx[ind << 1], mx[ind << 1 | 1]);
mn[ind] = min(mn[ind << 1], mn[ind << 1 | 1]);
}
inline int Get(int ind, int l, int r, int x, int y, int mode)
{
if (r < x || y < l)
{
return (mode ? 1000000000 : -1);
}
if (x <= l && r <= y)
{
return mx[ind];
}
int m = (l + r) >> 1;
if (mode)
{
return min(Get(ind << 1, l, m, x, y, mode), Get(ind << 1 | 1, m + 1, r, x, y, mode));
}
return max(Get(ind << 1, l, m, x, y, mode), Get(ind << 1 | 1, m + 1, r, x, y, mode));
}
} st1, st2;
int n, m, b[300000], c, d, l, r, mid, res = -1;
array<int, 3> a[150000];
int main()
{
setup();
cin >> n;
for (int i = 0; i < n; ++i)
{
cin >> a[i][0] >> a[i][1] >> a[i][2];
b[i << 1] = a[i][1];
b[i << 1 | 1] = a[i][2];
}
sort(a, a + n);
sort(b, b + 2 * n);
m = unique(b, b + 2 * n) - b;
for (int i = 0, j = 0; i < n;)
{
while (j < n && a[i][0] == a[j][0])
{
a[j][1] = lower_bound(b, b + m, a[j][1]) - b;
a[j][2] = lower_bound(b, b + m, a[j][2]) - b;
l = a[j][1] + 1;
r = m - 1;
while (l <= r)
{
mid = (l + r) >> 1;
d = st1.Get(1, 0, m - 1, mid, m - 1, 0);
if (a[j][2] < d)
{
l = mid + 1;
res = max(res, a[j][0] + b[mid] + b[d]);
}
else
{
r = mid - 1;
}
}
j++;
}
while (i < j)
{
c = st2.Get(1, 0, m - 1, 0, a[i][1] - 1, 0);
if (c != -1)
{
st1.Update(1, 0, m - 1, a[i][1], c);
}
c = -1;
l = a[i][1] + 1;
r = m - 1;
while (l <= r)
{
mid = (l + r) >> 1;
d = st2.Get(1, 0, m - 1, mid, m - 1, 1);
if (d != -1 && a[i][2] > d)
{
c = mid;
l = mid + 1;
}
else
{
r = mid - 1;
}
}
if (c != -1)
{
st1.Update(1, 0, m - 1, c, a[i][2]);
}
st2.Update(1, 0, m - 1, a[i][1], a[i][2]);
i++;
}
}
cout << res;
return 0;
}
