foo.c: In function 'main':
foo.c:6:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for (;a<=b;a++)
  ^~~
foo.c:8:6: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
      printf ("%d",s);
      ^~~~~~
foo.c:5:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d",&a,&b);
  ^~~~~~~~~~~~~~~~~~~~
foo.c:7:7: warning: 's' may be used uninitialized in this function [-Wmaybe-uninitialized]
      s=s+a;
      ~^~~~

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