#include<stdio.h>
int factorsum(int number);
void PrintPN(int m,int n);
main()
{
int i, m, n;
scanf("%d %d",&m,&n);
if(factorsum(m)==m) printf("%d is a perfect number\n",m);
if(factorsum(n)==n) printf("%d is a perfect number\n",n);
PrintPN(m,n);
}
int factorsum(int number)
{
int i,sum=1;
for(i=2;i<number;i++)
if(number%i==0) sum=sum+i;
return sum;
}
void PrintPN(int m,int n)
{
int count=0;
int i,j;
for(i=m;i<=n;i++)
{
if(factorsum(i)==i) /*判断是否为完数*/
{
count++;
printf("%d = 1",i);
for(j=2;j<i;j++)
{
if(i%j==0) printf(" + %d",j);
}
printf("\n");
}
}
if(count==0) printf("No perfect number");
}