The Closest Pair

题意翻译

给你两个整数 n , k （ n 即为代码中的 n ),你需要构造一组输入，让程序结束时 tot 的值大于 k ，如果不可能，就输出 no solution 。

题目描述

Currently Tiny is learning Computational Geometry. When trying to solve a problem called "The Closest Pair Of Points In The Plane", he found that a code which gave a wrong time complexity got Accepted instead of Time Limit Exceeded. The problem is the follows. Given $ n $ points in the plane, find a pair of points between which the distance is minimized. Distance between $ (x_{1},y_{1}) $ and $ (x_{2},y_{2}) $ is . The pseudo code of the unexpected code is as follows: `<br></br>input n<br></br>for i from 1 to n<br></br> input the i-th point's coordinates into p[i]<br></br>sort array p[] by increasing of x coordinate first and increasing of y coordinate second<br></br>d=INF //here INF is a number big enough<br></br>tot=0<br></br>for i from 1 to n<br></br> for j from (i+1) to n<br></br> ++tot<br></br> if (p[j].x-p[i].x>=d) then break //notice that "break" is only to be<br></br> //out of the loop "for j"<br></br> d=min(d,distance(p[i],p[j]))<br></br>output d<br></br>`Here, $ tot $ can be regarded as the running time of the code. Due to the fact that a computer can only run a limited number of operations per second, $ tot $ should not be more than $ k $ in order not to get Time Limit Exceeded. You are a great hacker. Would you please help Tiny generate a test data and let the code get Time Limit Exceeded?

输入输出格式

输入格式

A single line which contains two space-separated integers $ n $ and $ k $ ( $ 2<=n<=2000 $ , $ 1<=k<=10^{9} $ ).

输出格式

If there doesn't exist such a data which let the given code get TLE, print "no solution" (without quotes); else print $ n $ lines, and the $ i $ -th line contains two integers $ x_{i},y_{i} $ $ (|x_{i}|,|y_{i}|<=10^{9}) $ representing the coordinates of the $ i $ -th point. The conditions below must be held: - All the points must be distinct. - $ |x_{i}|,|y_{i}|<=10^{9} $ . - After running the given code, the value of $ tot $ should be larger than $ k $ .

输入输出样例

输入样例 #1

4 3

输出样例 #1

0 0
0 1
1 0
1 1

输入样例 #2

2 100

输出样例 #2

no solution