/in/foo.cc: In function 'int main()':
/in/foo.cc:13:9: error: 'strcpy' was not declared in this scope
   13 |         strcpy(b, a);
      |         ^~~~~~
/in/foo.cc:2:1: note: 'strcpy' is defined in header '<cstring>'; did you forget to '#include <cstring>'?
    1 | #include<iostream>
  +++ |+#include <cstring>
    2 | using namespace std;
/in/foo.cc:14:20: error: 'strlen' was not declared in this scope
   14 |         int lena = strlen(a);
      |                    ^~~~~~
/in/foo.cc:14:20: note: 'strlen' is defined in header '<cstring>'; did you forget to '#include <cstring>'?