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())))