error[E0425]: cannot find value `n` in this scope
  --> /w/foo.rs:13:5
   |
13 |     n = a[0];
   |     ^ help: a local variable with a similar name exists: `a`

error[E0425]: cannot find value `n` in this scope
  --> /w/foo.rs:29:19
   |
29 |     for i in 0 .. n as usize {
   |                   ^ help: a local variable with a similar name exists: `a`

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0425`.

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