2017 ACM-ICPC 亚洲区（西安赛区）网络赛 F. Trig Function(切比雪夫多项式)
f(cos(x))=cos(n∗x) holds for all xx.Given two integers nn and mm, you need to calculate the coefficient of x^mxm in f(x)f(x), modulo 998244353998244353.Input FormatMultiple test case
