#include <fstream>
#include <iostream>
#include <math.h>

int main() {
  std::ifstream inputFile("input");
  if (!inputFile.is_open()) {
    std::cerr << "Error opening file." << std::endl;
    return 1;
  }

  long long count = 0;
  std::string line;
  while (std::getline(inputFile, line)) {
    int next = 0;
    for (int i = 12; i > 0; --i) {
      int max = 0;
      for (int j = next; j <= line.length() - i; ++j) {
        if (line[j] - '0' > max) {
          max = line[j] - '0';
          next = j + 1;
        }
      }
      count += max * pow(10, i - 1);
    }
  }

  std::cout << count << std::endl;

  inputFile.close();
  return 0;
}