import java.io.*;
import java.util.*;

class ContestReader {
  private BufferedReader reader;
  private StringTokenizer tokenizer;
  
  ContestReader(InputStream in) {
    reader = new BufferedReader(new InputStreamReader(in));
  }
  
  public String next() {
    while (tokenizer == null || !tokenizer.hasMoreTokens()) {
      try {
        tokenizer = new java.util.StringTokenizer(reader.readLine());
      } catch (Exception e) {
        throw new RuntimeException(e);
      }
    }
    return tokenizer.nextToken();
  }
  
  public int nextInt() {
    return Integer.parseInt(next());
  }
  
  public long nextLong() {
    return Long.parseLong(next());
  }
  
  public double nextDouble() {
    return Double.parseDouble(next());
  }
  
  public int[] nextIntArray(int n) {
    int[] array = new int[n];
    for (int i = 0; i < n; i++) {
      array[i] = nextInt();
    }
    return array;
  }
  
  public long[] nextLongArray(int n) {
    long[] array = new long[n];
    for (int i = 0; i < n; i++) {
      array[i] = nextLong();
    }
    return array;
  }
}

class Solver {
  long n;
  ArrayList<Long> factors;
  ArrayList<Integer> factorCounts;
  
  private long dfs(long f, int index) {
    if (index == factors.size()) {
      long m = n / f - 1;
      if (m > f) {
        return m;
      } else {
        return 0;
      }
    }
    
    long sum = 0;
    for (int i = 0; i <= factorCounts.get(index); i++) {
      sum += dfs(f, index+1);
      f *= factors.get(index);
    }
    return sum;
  }
  
  
  public long solve(long n) {
    this.n = n;
    factors = new ArrayList<>();
    factorCounts = new ArrayList<>();
    
    long nTemp = n;
    for (long f = 2; f * f <= nTemp; f++) {
      int count = 0;
      while (nTemp % f == 0) {
        nTemp /= f;
        count++;
      }
      if (count > 0) {
        factors.add(f);
        factorCounts.add(count);
      }
    }
    if (nTemp > 1) {
      factors.add(nTemp);
      factorCounts.add(1);
    }
//    System.err.println("factors");
    return dfs(1, 0);
  }
}

class Algorithm {
  private static void swap(Object[] list, int a, int b) {
    Object tmp = list[a];
    list[a] = list[b];
    list[b] = tmp;
  }
  
  public static <T extends Comparable<? super T>> boolean nextPermutation(T[] ts) {
    int rightMostAscendingOrderIndex = ts.length - 2;
    while (rightMostAscendingOrderIndex >= 0 &&
        ts[rightMostAscendingOrderIndex].compareTo(ts[rightMostAscendingOrderIndex + 1]) >= 0) {
      rightMostAscendingOrderIndex--;
    }
    if (rightMostAscendingOrderIndex < 0) {
      return false;
    }
    
    int rightMostGreatorIndex = ts.length - 1;
    while (ts[rightMostAscendingOrderIndex].compareTo(ts[rightMostGreatorIndex]) >= 0) {
      rightMostGreatorIndex--;
    }
    
    swap(ts, rightMostAscendingOrderIndex, rightMostGreatorIndex);
    for (int i = 0; i < (ts.length - rightMostAscendingOrderIndex - 1) / 2; i++) {
      swap(ts, rightMostAscendingOrderIndex + 1 + i, ts.length - 1 - i);
    }
    return true;
  }
}

public class Main {
  
  
  private static void execute(ContestReader reader, PrintWriter out) {
    long n = reader.nextLong();
    out.println(new Solver().solve(n));
  }
  
  public static void main(String[] args) {
    ContestReader reader = new ContestReader(System.in);
    PrintWriter out = new PrintWriter(System.out);
    execute(reader, out);
    out.flush();
  }
}



Measured memory_bytes: 21460