#include <bits/stdc++.h>
using namespace std;
int main() {
string s;
cout << "Enter String: ";
cin >> s;
int start = 0, end = s.length() - 1;
while (start < end) {
// XOR-based swapping without extra storage
s[start] ^= s[end];
s[end] ^= s[start];
s[start] ^= s[end];
start++;
end--;
}
cout << "Reverse String = " << s << endl;
return 0;
}