/in/foo.cc: In function 'int main()':
/in/foo.cc:5:1: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
 gets(a1);
 ^~~~
In file included from /usr/include/c++/6/cstdio:42:0,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:46,
                 from /in/foo.cc:1:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.cc:5:8: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
 gets(a1);
        ^
In file included from /usr/include/c++/6/cstdio:42:0,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:46,
                 from /in/foo.cc:1:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.cc:6:24: error: cannot convert 'long long int*' to 'const char*' for argument '1' to 'size_t strlen(const char*)'
 for(int i=0;i<=strlen(a);i++)
                        ^
/in/foo.cc:4:23: warning: unused variable 'p' [-Wunused-variable]
 char a1[90];long long p,a[90];
                       ^