n = int(input())

a = float("inf")
dp = [a] * (n+2)
dp[1] = 0

for i in range(1, n+2):
    for k in range(1, n+2):
        if i * k > n:
            break
        else:
            dp[i * k] = min(dp[i] + k, dp[i * k])
print(dp[n])