#include <string>
#include <iostream>
#include <algorithm>
 
std::string convert(unsigned long value, unsigned long base) {
    std::string rc;
    do {
        rc.push_back("0123456789abcde"[value % base]);
    } while (value /= base);
    std::reverse(rc.begin(), rc.end());
    return rc;
}
 
int main() {
    std::cout << convert(100, 16) << '\n';
    std::cout << convert(100, 10) << '\n';
    std::cout << convert(100, 2) << '\n';
    std::cout << convert(100, 1) << '\n';
}

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