/in/foo.c: In function 'main':
/in/foo.c:6:8: error: expected '=', ',', ';', 'asm' or '__attribute__' before '==' token
  int xx==x,y=0;
        ^~
/in/foo.c:6:8: error: expected expression before '==' token
/in/foo.c:7:8: error: 'xx' undeclared (first use in this function)
  while(xx>0)
        ^~
/in/foo.c:7:8: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:10:4: error: 'y' undeclared (first use in this function)
    y=y*10+xl;
    ^