In file included from /usr/include/stdio.h:74:0,
                 from /usr/include/c++/6/cstdio:42,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:46,
                 from /in/foo.cc:1:
/in/foo.cc: In function 'int main()':
/in/foo.cc:8:19: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
  while(c=getchar!=EOF)
                   ^
/in/foo.cc:13:10: error: 'n' was not declared in this scope
  while(i<n&&j<n&&k<n)
          ^