#include<stdio.h>
int main()
{
	int n,i;
	long long j,l[10005],r[10005],sum[10005];
	scanf("%d",&n);
	for(i=1;i<=n;i++)
	{
		scanf("%lld %lld",&l[i],&r[i]);
		sum[i]=(l[i]+r[i])*(r[i]-l[i]+1)/2;
		sum[i]%=9;
	}
	for(i=1;i<=n;i++)
	{
		printf("%lld\n",sum[i]);
	}
	return 0;
}

我感觉没什么问题啊