/in/foo.c: In function 'main':
/in/foo.c:6:19: warning: unused variable 'dd' [-Wunused-variable]
     int y,m,d,i,n,dd=0;
                   ^~
/in/foo.c:6:17: warning: unused variable 'n' [-Wunused-variable]
     int y,m,d,i,n,dd=0;
                 ^
/in/foo.c: In function 'lamb':
/in/foo.c:29:11: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  if(y%4==0&&y%100!=0||y%400==0)
     ~~~~~~^~~~~~~~~~
/in/foo.c: In function 'Day':
/in/foo.c:52:9: warning: 'day' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return day;
         ^~~