读题读了半天。看明白了特么就是一道大水题Orz
The input to your program will be the lower triangular section of A. That is, the second line of input will contain one entry, A(2,1). The next line will contain two entries, A(3,1) and A(3,2), and so on.
输入的话就是看这里，，第一行表示2-1要多少，第二行3-1，3-2,第三行是4-1,4-2,4-3。以此类推。