/in/foo.cc: In function 'int main()':
/in/foo.cc:8:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int j=1;j<=i;++j){
              ~^~~
/in/foo.cc:10:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while(now<max){
         ~~~^~~~
/in/foo.cc:12:12: error: lvalue required as left operand of assignment
     now++*=2;
            ^