Codeforces 337A Puzzles

Puzzlestime limit:1000msmemory limit:262144kbthis problem'll be judged onCodeforces. Original id:337a
64-bit integer IO format: %i64d Java class name: (any) The end of the school year was near and Ms Manana, the teacher, would soon has to say goodbye to a yet another class. She decided to prepare a goodbye present n students and give each of them a jigsaw puzzle (which, as Wikipedia states, was a tiling puzzle that require s the assembly of numerous small, often oddly shaped, interlocking and tessellating pieces).

The shop assistant told the teacher a there are  m  puzzles in the They might differ in difficulty and size. Specifically, the first jigsaw puzzle consists Of  F 1  pieces, the second one consists Of  F 2  Pieces and so on.

Ms. Manana doesn ' t want to upset the children, so she decided that the difference between the numbers of pieces in her pre Sents must be as small as possible. Let A is the number of pieces in the largest puzzle so the teacher buys and B be the number of Pieces in the smallest such puzzle. She wants to choose such n puzzles, A - B is minimum possible. Help the teacher and find the least possible value of A - B.

Input

The first line contains space-separated integers n and m (2≤ n ≤ m ≤50). The second line contains m space-separated integers f1, F2, ..., f m (4≤ fi ≤1000)-the quantities of pieces in the puzzles sold in the shop.

Output

Print A single integer-the least possible difference the teacher can obtain.

Sample InputInput

4 6
10 12 10 7 5 22

Output

5

Hint

Sample 1. The class has 4 students. The shop sells 6 puzzles. If Ms Manana buys the first four puzzles consisting of ten, and 7 pieces correspondingly, then the difference betwe En the sizes of the largest and the smallest puzzle would be equal to 5. It's impossible to obtain a smaller difference. Note that the teacher can also buy puzzles 1, 3, 4 and 5 to obtain the difference 5.

SourceCodeforces Round #196 (Div. 2) Problem solving: a silly problem.

1#include <bits/stdc++.h>2 using namespacestd;3 Const intMAXN = -;4 intd[maxn],n,m;5 intMain () {6scanf"%d%d",&n,&m);7      for(inti =0; I < m; ++i)8scanf"%d", d+i);9Sort (d,d+m);Ten     intRET =Int_max; One      for(inti =0+ N-1; I < m; ++i) Aret = min (ret,d[i]-d[i-n+1]); -printf"%d\n", ret); -     return 0; the}

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Codeforces 337A Puzzles