p=[1]*101
p[0]=0
p[1]=0
for i in range(2,101):
  if p[i]:
    for j in range(i+i,101,i):
      p[j]=0
a=0
l,r=map(int,input().split())
for i in range(l,r+1):
  a+=(i**3-i**2+i**1+1)*p[i]
print(a)