/in/foo.cc: In function 'int main()':
/in/foo.cc:42:15: warning: format '%s' expects argument of type 'char*', but argument 2 has type 'char (*)[200010]' [-Wformat=]
  scanf("%s",&s);
               ^
/in/foo.cc: In function 'void solve()':
/in/foo.cc:12:13: warning: 'first' may be used uninitialized in this function [-Wmaybe-uninitialized]
   if(s[first-1]==s[last+1])
        ~~~~~^~
/in/foo.cc:16:6: note: 'first' was declared here
 void solve()
      ^~~~~