 class="kw">function</span><span class="op">(</span><span class="va">X_0</span>, <span class="va">K</span> <span class="op">=</span> <span class="fl">2000</span>, <span class="va">gr</span> <span class="op">=</span> <span class="fl">1</span><span class="op">)</span><span class="op">{</span>
    <span class="va">X_1</span> <span class="op">&lt;-</span> <span class="va">X_0</span> <span class="op">+</span> <span class="va">gr</span> <span class="op">*</span> <span class="va">X_0</span> <span class="op">*</spa