#include <iostream>
#include <string>
using namespace std;
int main() {
string s = "ABCDEFGHIJK";
for(size_t i = 0; i + 3 < s.length(); i += 3)
{
s[i] ^= s[i + 2];
s[i + 2] ^= s[i];
s[i] ^= s[i + 2];
}
cout << s << endl;
}
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