function romanToInt(s) {
  const values = {
    I: 1,
    V: 5,
    X: 10,
    L: 50,
    C: 100,
    D: 500,
    M: 1000,
  };
  let total = 0;
  for (let i = 0; i < s.length; i++) {
    const current = values[s[i]];
    const next = i + 1 < s.length ? values[s[i + 1]] : 0;
    total += current < next ? -current : current;
  }
  return total;
}