题解

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