/in/foo.c: In function 'Fun':
/in/foo.c:5:11: warning: unused variable 'j' [-Wunused-variable]
     int i,j,sum=0;
           ^
/in/foo.c:5:9: warning: unused variable 'i' [-Wunused-variable]
     int i,j,sum=0;
         ^
/in/foo.c: In function 'main':
/in/foo.c:17:13: warning: unused variable 'k' [-Wunused-variable]
     int i,j,k,n,sum;
             ^