/in/foo.cc: In function 'void multiply(int, const LL (&)[70][70], const LL (&)[70][70], LL (&)[70][70], LL)':
/in/foo.cc:33:29: error: 'memcpy' was not declared in this scope
  memcpy(C, t, sizeof(matrix));
                             ^
/in/foo.cc: In function 'void power_mod(int, const LL (&)[70][70], LL, LL, LL (&)[70][70])':
/in/foo.cc:40:31: error: 'memcpy' was not declared in this scope
  memcpy(cur, A, sizeof(matrix));
                               ^
/in/foo.cc: In function 'LL sum_power_mod(const LL (&)[70][70], LL, LL)':
/in/foo.cc:53:29: error: 'memcpy' was not declared in this scope
  memcpy(B, A, sizeof(matrix));
                             ^