import sys # sys.setrecursionlimit(200005) int1 = lambda x: int(x)-1 pDB = lambda *x: print(*x, end="\n", file=sys.stderr) p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr) def II(): return int(sys.stdin.readline()) def LI(): return list(map(int, sys.stdin.readline().split())) def LLI(rows_number): return [LI() for _ in range(rows_number)] def LI1(): return list(map(int1, sys.stdin.readline().split())) def LLI1(rows_number): return [LI1() for _ in range(rows_number)] def SI(): return sys.stdin.readline().rstrip() # dij = [(0, 1), (-1, 0), (0, -1), (1, 0)] # dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)] # inf = (1<<63)-1 inf = (1 << 31)-1 # md = 10**9+7 md = 998244353 def factors(a): if a <= 0: return [0] dd0, dd1 = [], [] for d in range(1, round(a**0.5)+1): if a%d: continue dd0.append(d) dd1.append(a//d) if dd0[-1] == dd1[-1]: dd1.pop() return dd0+dd1[::-1] print(sum(f for f in factors(II())))