#include<stdio.h> int count(int a,int b){ int count=0; for(int i=a;i<=b;i++){ int sum=0; int y=i; while(y!=0){ sum=sum+y%10; y/=10; } if(sum%5==0){ count++; } } return count; } int main(){ int a=0,b=0; scanf("%d %d",&a,&b); printf("%d",count(a,b)); return 0; }