/in/foo.c: In function 'main':
/in/foo.c:7:3: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   for(i=2;i<=n;i++)
   ^~~
/in/foo.c:9:4: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
    printf("%d",a);
    ^~~~~~
/in/foo.c:9:4: warning: 'a' may be used uninitialized in this function [-Wmaybe-uninitialized]
    printf("%d",a);
    ^~~~~~~~~~~~~~