import math
def divsum(n):
    result=0
    for i in range(2,(int)(math.sqrt(n))+1):
        if(n%i==0):
            if(i==n/i):
                result=result+i
            else:
                result=result+(i+n//i)
    return (result+n+1)
number=int(input())
value=0
for i in range(1,number+1):
    if((divsum(i)/i)-(divsum(i)//i)==float(1/2)):
        value=value+i
print(value)