Standard input is empty

[1]
[1,1]
[1,2,1]
[1,3,3,1]
[1,4,6,4,1]
[1,5,10,10,5,1]
[1,6,15,20,15,6,1]
[1,7,21,35,35,21,7,1]
[1,8,28,56,70,56,28,8,1]
[1,9,36,84,126,126,84,36,9,1]
[1,10,45,120,210,252,210,120,45,10,1]
[1,11,55,165,330,462,462,330,165,55,11,1]
[1,12,66,220,495,792,924,792,495,220,66,12,1]
[1,13,78,286,715,1287,1716,1716,1287,715,286,78,13,1]
[1,14,91,364,1001,2002,3003,3432,3003,2002,1001,364,91,14,1]
[1,15,105,455,1365,3003,5005,6435,6435,5005,3003,1365,455,105,15,1]
[1,16,120,560,1820,4368,8008,11440,12870,11440,8008,4368,1820,560,120,16,1]
[1,17,136,680,2380,6188,12376,19448,24310,24310,19448,12376,6188,2380,680,136,17,1]
[1,18,153,816,3060,8568,18564,31824,43758,48620,43758,31824,18564,8568,3060,816,153,18,1]
[1,19,171,969,3876,11628,27132,50388,75582,92378,92378,75582,50388,27132,11628,3876,969,171,19,1]