//ww:run-exit 7
// Migrated from 700_e2e row 101.
package main;
import bytes;
fn main() i32 = {
  let buf: [12]u8;
  buf[0] = 104u8; buf[1] = 101u8; buf[2] = 108u8; buf[3] = 108u8;
  buf[4] = 111u8; buf[5] = 44u8;  buf[6] = 32u8;  buf[7] = 119u8;
  buf[8] = 111u8; buf[9] = 114u8; buf[10] = 108u8; buf[11] = 100u8;
  let needle: [3]u8;
  needle[0] = 119u8; needle[1] = 111u8; needle[2] = 114u8;
  let r: (i32 | void) = bytes.index(buf[0:12], needle[0:3]);
  match (r) {
    case let i: i32 => return i;
    case void => return -1;
  };
  return 0;
};