a=int(input())

b=a+1
c=1

if a%2==0:

    while c<=a:
        if (a%c)==0:
            if (c + (a / c)) < b:
                b=c + a // c

        c += 1
        if (c*(a%c)+1)>a:
            break

else:
    while c<=a:
        if (a%c)==0:
            if (c + (a / c)) < b:
                b=c + a // c

        c += 2
        if (c*(a%c)+1)>a:
            break

print (b)