//ww:run-exit 3
// Migrated from 700_e2e row 71.
package main;
type error = str;
fn read(n: i64) (i64 | error) = {
  if (n < 0) { return "eof": error; };
  return n + 1;
};
fn main() i32 = {
  let r: (i64 | error) = read(-1);
  match (r) {
    case let v: i64 => return v: i32;
    case let e: error => return e.len: i32;
  };
  return 0;
};