foo.cc: In function 'int main()':
foo.cc:10:11: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
     gets(a);
           ^
In file included from /usr/include/stdio.h:862:0,
                 from foo.cc:1:
/usr/include/x86_64-linux-gnu/bits/stdio2.h:232:1: note: declared here
 gets (char *__str)
 ^~~~
foo.cc:13:5: error: 'strrev' was not declared in this scope
     strrev(b);
     ^~~~~~
foo.cc:13:5: note: suggested alternative: 'strsep'
     strrev(b);
     ^~~~~~
     strsep
foo.cc:17:9: error: '__int64' was not declared in this scope
         __int64 t=atoi(a)+atoi(b);
         ^~~~~~~
foo.cc:17:9: note: suggested alternative: '__int64_t'
         __int64 t=atoi(a)+atoi(b);
         ^~~~~~~
         __int64_t
foo.cc:18:14: error: 't' was not declared in this scope
         itoa(t,a,10);
              ^
foo.cc:18:9: error: 'itoa' was not declared in this scope
         itoa(t,a,10);
         ^~~~
foo.cc:18:9: note: suggested alternative: 'atol'
         itoa(t,a,10);
         ^~~~
         atol
foo.cc:27:5: error: unable to find numeric literal operator 'operator""printf'
     3printf("\n");
     ^~~~~~~
foo.cc:27:5: note: use -std=gnu++11 or -fext-numeric-literals to enable more built-in suffixes
foo.cc:10:9: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result [-Wunused-result]
     gets(a);
     ~~~~^~~

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