include <iostream>

include <string>

include <algorithm>

int main() {

int n, k;

std::cin >> n >> k;

std::string number = std::to_string(n);

int numDigits = number.length();

if (k >= numDigits) {

std::cout << "0" << std::endl;

} else {

std::sort(number.begin(), number.end(), std::greater<char>());

number = number.substr(0, numDigits - k);

std::cout << number << std::endl;

}

return 0;

}