/in/foo.c: In function 'main':
/in/foo.c:14:4: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
    if(x1%a==0)
    ^~
/in/foo.c:16:5: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'if'
     a++;
     ^
/in/foo.c:7:6: warning: unused variable 'a' [-Wunused-variable]
  int a;
      ^