Untitled

// SPDX-License-Identifier: UNLICENSED
pragma solidity 0.8.20;

contract PrecisionLoss2 {

    uint constant SMALLEST_RATE_PER_YEAR = 1; // 0.1%

    // 0.1% = 0.001
    //        0.001,000,000,000,000,000             (to have 18 decimals, add 15 decimals)
    //        0.001,000,000,000,000,000,000,000,000 (to have 27 decimals, add 24 decimals)
    //                                              (to have  x decimals, add x-3 decimals - 3)
    function smallestRatePerSecond(uint decimals) public pure returns (uint) {
        return (SMALLEST_RATE_PER_YEAR * (10 ** (decimals - 3)));
    }

    // (1e18 * re18) / 1e18 = 1*r e18
    // 1e18 * re27)
    // be18 * rex / 1ex

    function mulDiv18(uint balance, uint rateDecimals) external pure returns (uint) {
        return (balance * smallestRatePerSecond(rateDecimals)) / (365 days * (10 ** rateDecimals));
    }

    // i = 289302916 (with biggest decimals possible)
    // what is the smalles amount of decimals with the same i?

}