View Compilation Error

0_0_36693590_15811.cpp: In function 'int main()':
0_0_36693590_15811.cpp:13:27: error: cannot pass objects of non-trivially-copyable type 'std::string {aka class std::basic_string<char>}' through '...'
         scanf("%s%s", a, b);
                           ^
0_0_36693590_15811.cpp:13:27: error: cannot pass objects of non-trivially-copyable type 'std::string {aka class std::basic_string<char>}' through '...'