题解

#include <bits/stdc++.h>
using namespace std;
int a,b,ans=0; 
int main()
{
	cin>>a>>b;
	for(int i=a;i<=b;i++)
	{
		int t=i;
		while(t)
		{
			ans+=t%10;
			t/=10;
		}
	}
	cout<<ans;
	

    return 0;
}