using System; using System.IO; class Start { static void Solve() { long n;Inl(out n); var k = (long)(Math.Sqrt(n)+0.01); long ans = 0; if (k * k == n) ans -= k; for (int i = 1; i <= k; i++) if (n % i == 0) { ans += i + n / i; } Outl(ans); } const long MOD = 1000000007; static void Main() { var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false }; Console.SetOut(sw); Solve(); Console.Out.Flush(); } static void Inl(out long t) { t = long.Parse(Console.ReadLine()); } static void Inl(out string t) { t = Console.ReadLine(); } static void Inl(out char t) { t = Console.ReadLine()[0]; } static void Inl(out double t) { t = double.Parse(Console.ReadLine()); } static void Inl(ref T[] t) { string[] s = Console.ReadLine().Split(); Type type = typeof(T); int n = s.Length; if (type == LONG) for (int i = 0; i < n; i++) t[i] = (T)(object)long.Parse(s[i]); else if (type == STRING) for (int i = 0; i < n; i++) t[i] = (T)(object)s[i]; else if (type == CHAR) for (int i = 0; i < n; i++) t[i] = (T)(object)s[i][0]; else for (int i = 0; i < n; i++) t[i] = (T)(object)double.Parse(s[i]); } static void Inl(out T t, out U u) { string[] s = Console.ReadLine().Split(); In(out t, ref s, 0); In(out u, ref s, 1); } static void Inl(out T t, out U u, out V v) { string[] s = Console.ReadLine().Split(); In(out t, ref s, 0); In(out u, ref s, 1); In(out v, ref s, 2); } static void Inl(out T t, out U u, out V v, out W w) { string[] s = Console.ReadLine().Split(); In(out t, ref s, 0); In(out u, ref s, 1); In(out v, ref s, 2); In(out w, ref s, 3); } static void Inl(out T t, out U u, out V v, out W w, out X x) { string[] s = Console.ReadLine().Split(); In(out t, ref s, 0); In(out u, ref s, 1); In(out v, ref s, 2); In(out w, ref s, 3); In(out x, ref s, 4); } static void Inl(out T t, out U u, out V v, out W w, out X x, out Y y) { string[] s = Console.ReadLine().Split(); In(out t, ref s, 0); In(out u, ref s, 1); In(out v, ref s, 2); In(out w, ref s, 3); In(out x, ref s, 4); In(out y, ref s, 5); } static void Inl(out T t, out U u, out V v, out W w, out X x, out Y y, out Z z) { string[] s = Console.ReadLine().Split(); In(out t, ref s, 0); In(out u, ref s, 1); In(out v, ref s, 2); In(out w, ref s, 3); In(out x, ref s, 4); In(out y, ref s, 5); In(out z, ref s, 6); } static void In(out T t, ref string[] s, int i) { Type type = typeof(T); if (type == LONG) t = (T)(object)long.Parse(s[i]); else if (type == STRING) t = (T)(object)s[i]; else if (type == CHAR) t = (T)(object)s[i][0]; else t = (T)(object)double.Parse(s[i]); } static Type LONG = typeof(long); static Type STRING = typeof(string); static Type CHAR = typeof(char); static void Out(T t) { Console.Write(t); } static void Outl(T t) { Console.WriteLine(t); } static void Out(double d, int n) { string s = d.ToString("F" + n); Console.Write(s); } static void Outl(double d, int n) { string s = d.ToString("F" + n); Console.WriteLine(s); } static void Outl(ref T[] t) { Out(t[0]); for (int i = 1; i < t.Length; i++) Out(" " + t[i]); Out('\n'); } static void Swap(ref T a, ref T b) { T c = a; a = b; b = c; } static void Sort(ref T[] t) { Array.Sort(t); } static T Max(params T[] t) where T : IComparable { T max = t[0]; for (int i = 1; i < t.Length; i++) if (max.CompareTo(t[i]) < 0) max = t[i]; return max; } static T Min(params T[] t) where T : IComparable { T max = t[0]; for (int i = 1; i < t.Length; i++) if (max.CompareTo(t[i]) > 0) max = t[i]; return max; } struct Pair { public long a, b; public Pair(long a, long b) { this.a = a; this.b = b; } } static void aSort(ref Pair[] a) { Array.Sort(a, (x, y) => (int)(x.a - y.a)); } static void bSort(ref Pair[] a) { Array.Sort(a, (x, y) => (int)(x.b - y.b)); } }