import sys
import os


def main():
    if os.getenv("LOCAL"):
        sys.stdin = open("input.txt", "r")

    N = int(sys.stdin.readline().rstrip())

    ret = float('inf')
    for i in range(1, 10000000):
        q, mod = divmod(N, i)
        if mod == 0:
            j = N // i
            ret = min(ret, ((j-1)+(i-1)))

    print(ret)


if __name__ == '__main__':
    main()