View Compilation Error

0_0_37759664_24898.cpp: In instantiation of 'int fft::sz(const T&) [with T = std::vector<modnum<998244353> >]':
0_0_37759664_24898.cpp:46:16:   required from here
0_0_37759664_24898.cpp:39:61: error: 'size' was not declared in this scope
 template <typename T> int sz(const T& a) { return int(size(a)); }
                                                             ^
0_0_37759664_24898.cpp: In instantiation of 'int fft::sz(const T&) [with T = std::vector<int>]':
0_0_37759664_24898.cpp:63:30:   required from here
0_0_37759664_24898.cpp:39:61: error: 'size' was not declared in this scope