题解

#include<bits/stdc++.h>
using namespace std;
int main()
{
long long n,s=0,i,k,m=1,a,b;
cin>>a>>b;
for(i=a;i<=b;i++)
{
m=m*i;
while(m%10==0)
{
s++;
m=m/10;
}
m%=1000000000;
}
cout<<s;
return 0;
}