<p>For two strings <code>s</code> and <code>t</code>, we say &quot;<code>t</code> divides <code>s</code>&quot; if and only if <code>s = t + t + t + ... + t + t</code> (i.e., <code>t</code> is concatenated with itself one or more times).</p>

<p>Given two strings <code>str1</code> and <code>str2</code>, return <em>the largest string </em><code>x</code><em> such that </em><code>x</code><em> divides both </em><code>str1</code><em> and </em><code>str2</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> str1 = &quot;ABCABC&quot;, str2 = &quot;ABC&quot;
<strong>Output:</strong> &quot;ABC&quot;
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> str1 = &quot;ABABAB&quot;, str2 = &quot;ABAB&quot;
<strong>Output:</strong> &quot;AB&quot;
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> str1 = &quot;LEET&quot;, str2 = &quot;CODE&quot;
<strong>Output:</strong> &quot;&quot;
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= str1.length, str2.length &lt;= 1000</code></li>
	<li><code>str1</code> and <code>str2</code> consist of English uppercase letters.</li>
</ul>

class Solution {
public:
    string gcdOfStrings(string str1, string str2) {
        if(str1+str2 != str2+str1){
            return "";
        }
        string main = str1+str2;
        int i=0;
        string result = "";
        while(i<str1.size() && i<str2.size()){
            string temp = main.substr(0,i+1);
            if(str1.size()%temp.size() == 0 && str2.size()%temp.size()==0){
                int k1 = str1.size()/temp.size();
                int k2 = str2.size()/temp.size();
                string generated1 = "";
                string generated2 = "";
                for(int i=0;i<k1;i++){
                    generated1 += temp;
                }
                for(int i=0;i<k2;i++){
                    generated2 += temp;
                }
                if(generated1 == str1 && generated2 == str2){
                    result = temp;
                }
            }
            i++;
        }
        return result;
    }
};
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