// SPDX-License-Identifier: UNLICENSED
pragma solidity 0.8.28;

contract Counter {
  uint256 public x;

  event Increment(uint256 by);

  function inc() external {
    x += 1;
    emit Increment(1);
  }

  function incBy(uint256 by) external {
    require(by > 0, "Counter: increment must be positive");
    x += by;
    emit Increment(by);
  }
}