View Compilation Error

0_0_26109356_12643.cpp: In function 'int main()':
0_0_26109356_12643.cpp:34:29: error: cannot pass objects of non-trivially-copyable type 'std::string {aka class std::basic_string<char>}' through '...'
  while (scanf("%s%s", s1, s2)) {
                             ^
0_0_26109356_12643.cpp:34:29: error: cannot pass objects of non-trivially-copyable type 'std::string {aka class std::basic_string<char>}' through '...'