foo.c: In function 'main':
foo.c:17:3: warning: statement with no effect [-Wunused-value]
   for (start; start < end + 1; start++)
   ^~~
foo.c:14:2: warning: 'M' is used uninitialized in this function [-Wuninitialized]
  for (int i = 0; i < M; i++)
  ^~~
foo.c:22:2: warning: 'L' is used uninitialized in this function [-Wuninitialized]
  for (int i = 0; i < L + 1; i++)
  ^~~
foo.c:10:6: warning: 'end' may be used uninitialized in this function [-Wmaybe-uninitialized]
  int end;
      ^~~
foo.c:9:6: warning: 'start' may be used uninitialized in this function [-Wmaybe-uninitialized]
  int start;
      ^~~~~

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