Farmer John has acquired a set of $N$ ($2 \le N \le 2,000$) touchy cows who are conveniently numbered 1..$N$. They really hate being too close to other cows. A lot.
FJ has recorded the integer $X_{i}$,$Y_{i}$ coordinates of every cow i ($1 \le X_{i} \le 100,000; 1 \le Y_{i} \le 100,000$).
Among all those cows, exactly two of them are closest together. FJ would like to spread them out a bit. Determine which two are closest together and print their cow id numbers (i) in numerical order.
By way of example, consider this field of cows (presented on a typewriter grid that has slightly different proportions than you might expect):
10 | . . . . . . . 3 . . . . .
9 | . 1 . . 2 . . . . . . . .
8 | . . . . . . . . . . . . .
7 | . . . . . . . . . . 4 . .
6 | . . . . . . 9 . . . . . .
5 | . 8 . . . . . . . . . . .
4 | . . . . . 7 . . . . . . .
3 | . . . . . . . . . 5 . . .
2 | . . . . . . . . . . . . .
1 | . . . . 6 . . . . . . . .
0 ---------------------------
1 1 1 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3Quick visual inspection shows that cows 7 and 9 are closest together (the distance separating them is $\mathrm{sqrt}(1*1+2*2) = \mathrm{sqrt}(5)$, so the output would be '7 9' on a single line (without quotes, of course).
Input
- Line 1: A single integer: $N$
- Lines 2..$N$+1: Line i contains the coordinates of cow i expressed as two space-separated integers: $X_{i}$ and $Y_{i}$
Output
- Line 1: The two numerical IDs of the closest pair of cows (sorted)
Examples
Input 1
9 2 9 5 9 8 10 11 7 10 3 5 1 6 4 2 5 7 6
Output 1
7 9
As in the example.
Problem credits: Rob Kolstad, 2009