foo.cc: In function 'int main()':
foo.cc:6:15: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
   while(gets(s)){
               ^
In file included from /usr/include/stdio.h:862:0,
                 from /usr/include/c++/7/cstdio:42,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:46,
                 from foo.cc:1:
/usr/include/x86_64-linux-gnu/bits/stdio2.h:232:1: note: declared here
 gets (char *__str)
 ^~~~
foo.cc:8:19: error: 'n' was not declared in this scope
     for(int i=0;i<n;i++){
                   ^

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