1
var getSmallestString = function (n, k) {
2
  k -= n;
3
  let alpha = "_bcdefghijklmnopqrstuvwxy_",
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    ans = "z".repeat(~~(k / 25));
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  if (k % 25) ans = alpha[k % 25] + ans;
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  return ans.padStart(n, "a");
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};