foo.c: In function 'main':
foo.c:9:2: warning: statement with no effect [-Wunused-value]
    9 |  for (i; i < n; i++) {
      |  ^~~
foo.c:14:7: warning: unused variable 'flag' [-Wunused-variable]
   14 |   int flag = 1;
      |       ^~~~
foo.c:5:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    5 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
foo.c:10:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   10 |   scanf("%d", &a[i]);
      |   ^~~~~~~~~~~~~~~~~~

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