CF616E.Sum of Remainders

Calculate the value of the sum: $n$ mod $1$ + $n$ mod $2$ + $n$ mod $3$ + ... + $n$ mod $m$ . As the result can be very large, you should print the value modulo $10^{9}+7$ (the remainder when divided by $10^{9}+7$ ).

The modulo operator $a$ mod $b$ stands for the remainder after dividing $a$ by $b$ . For example $10$ mod $3$ = $1$ .

The only line contains two integers $n,m$ ( $1<=n,m<=10^{13}$ ) — the parameters of the sum.

Print integer $s$ — the value of the required sum modulo $10^{9}+7$ .