Problem: <image>

To monitor cryptocurrency exchange rates trader William invented a wonderful device consisting of n lights arranged in a row. The device functions in the following way:

Initially, all lights on William's device are turned off. At the beginning of a new iteration the device randomly, with a uniform distribution, picks a light that is turned off and turns it on, telling William which cryptocurrency he should invest in. After this iteration if any k consecutive lights contain more than one turned on light, then the device finishes working.

William doesn't like uncertainty, so he wants you to calculate the expected value of the number of lights that are turned on in the device after it finishes working.

Input

Each test contains multiple test cases. The first line contains the number of test cases t (1 ≤ t ≤ 10). Description of the test cases follows.

The only line for each test case contains two integers n and k (2 ≤ k ≤ n ≤ 10^5), which are the total number of lights and the length of subsegment of lights that are being checked, respectively.

Output

For each test case print the answer, modulo 10^9+7. 

Formally, let M = 10^9+7. It can be shown that the answer can be expressed as an irreducible fraction p/q, where p and q are integers and q not ≡ 0 \pmod{M}. Output the integer equal to p ⋅ q^{-1} mod M. In other words, output such an integer x that 0 ≤ x < M and x ⋅ q ≡ p \pmod{M}.

Example

Input


3
3 2
15 2
40 15


Output


333333338
141946947
329622137

Note

Explanation of the first sample test case:

Let's write out all possible sequences of light toggles, which will make the device complete its operation:

  1. (1, 2) — 2 lights are turned on 
  2. (1, 3, 2) — 3 lights are turned on 
  3. (2, 1) — 2 lights are turned on 
  4. (2, 3) — 2 lights are turned on 
  5. (3, 2) — 2 lights are turned on 
  6. (3, 1, 2) — 3 lights are turned on 



Then the final expected value will be equal to 2/6 + 3/6 + 2/6 + 2/6 + 2/6 + 3/6 = 14/6 = 7/3. 

Then the required output will be 333333338, since 333333338 ⋅ 3 ≡ 7 \pmod{10^9+7}.

Solution (in CPP):

Solution:
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("inline")
#include<bits/stdc++.h>
using namespace std;
#define MD (1000000007U)
void*wmem;
char memarr[96000000];
template<class T> inline void walloc1d(T **arr, int x, void **mem = &wmem){
  static int skip[16] = {0, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1};
  (*mem) = (void*)( ((char*)(*mem)) + skip[((unsigned long long)(*mem)) & 15] );
  (*arr)=(T*)(*mem);
  (*mem)=((*arr)+x);
}
template<class T> inline void walloc1d(T **arr, int x1, int x2, void **mem = &wmem){
  walloc1d(arr, x2-x1, mem);
  (*arr) -= x1;
}
struct Modint{
  unsigned val;
  Modint(){
    val=0;
  }
  Modint(int a){
    val = ord(a);
  }
  Modint(unsigned a){
    val = ord(a);
  }
  Modint(long long a){
    val = ord(a);
  }
  Modint(unsigned long long a){
    val = ord(a);
  }
  inline unsigned ord(unsigned a){
    return a%MD;
  }
  inline unsigned ord(int a){
    a %= (int)MD;
    if(a < 0){
      a += MD;
    }
    return a;
  }
  inline unsigned ord(unsigned long long a){
    return a%MD;
  }
  inline unsigned ord(long long a){
    a %= (int)MD;
    if(a < 0){
      a += MD;
    }
    return a;
  }
  inline unsigned get(){
    return val;
  }
  inline Modint &operator++(){
    val++;
    if(val >= MD){
      val -= MD;
    }
    return *this;
  }
  inline Modint &operator--(){
    if(val == 0){
      val = MD - 1;
    }
    else{
      --val;
    }
    return *this;
  }
  inline Modint operator++(int a){
    Modint res(*this);
    val++;
    if(val >= MD){
      val -= MD;
    }
    return res;
  }
  inline Modint operator--(int a){
    Modint res(*this);
    if(val == 0){
      val = MD - 1;
    }
    else{
      --val;
    }
    return res;
  }
  inline Modint &operator+=(Modint a){
    val += a.val;
    if(val >= MD){
      val -= MD;
    }
    return *this;
  }
  inline Modint &operator-=(Modint a){
    if(val < a.val){
      val = val + MD - a.val;
    }
    else{
      val -= a.val;
    }
    return *this;
  }
  inline Modint &operator*=(Modint a){
    val = ((unsigned long long)val*a.val)%MD;
    return *this;
  }
  inline Modint &operator/=(Modint a){
    return *this *= a.inverse();
  }
  inline Modint operator+(Modint a){
    return Modint(*this)+=a;
  }
  inline Modint operator-(Modint a){
    return Modint(*this)-=a;
  }
  inline Modint operator*(Modint a){
    return Modint(*this)*=a;
  }
  inline Modint operator/(Modint a){
    return Modint(*this)/=a;
  }
  inline Modint operator+(int a){
    return Modint(*this)+=Modint(a);
  }
  inline Modint operator-(int a){
    return Modint(*this)-=Modint(a);
  }
  inline Modint operator*(int a){
    return Modint(*this)*=Modint(a);
  }
  inline Modint operator/(int a){
    return Modint(*this)/=Modint(a);
  }
  inline Modint operator+(long long a){
    return Modint(*this)+=Modint(a);
  }
  inline Modint operator-(long long a){
    return Modint(*this)-=Modint(a);
  }
  inline Modint operator*(long long a){
    return Modint(*this)*=Modint(a);
  }
  inline Modint operator/(long long a){
    return Modint(*this)/=Modint(a);
  }
  inline Modint operator-(void){
    Modint res;
    if(val){
      res.val=MD-val;
    }
    else{
      res.val=0;
    }
    return res;
  }
  inline operator bool(void){
    return val!=0;
  }
  inline operator int(void){
    return get();
  }
  inline operator long long(void){
    return get();
  }
  inline Modint inverse(){
    int a = val;
    int b = MD;
    int u = 1;
    int v = 0;
    int t;
    Modint res;
    while(b){
      t = a / b;
      a -= t * b;
      swap(a, b);
      u -= t * v;
      swap(u, v);
    }
    if(u < 0){
      u += MD;
    }
    res.val = u;
    return res;
  }
  inline Modint pw(unsigned long long b){
    Modint a(*this);
    Modint res;
    res.val = 1;
    while(b){
      if(b&1){
        res *= a;
      }
      b >>= 1;
      a *= a;
    }
    return res;
  }
  inline bool operator==(int a){
    return ord(a)==val;
  }
  inline bool operator!=(int a){
    return ord(a)!=val;
  }
}
;
inline Modint operator+(int a, Modint b){
  return Modint(a)+=b;
}
inline Modint operator-(int a, Modint b){
  return Modint(a)-=b;
}
inline Modint operator*(int a, Modint b){
  return Modint(a)*=b;
}
inline Modint operator/(int a, Modint b){
  return Modint(a)/=b;
}
inline Modint operator+(long long a, Modint b){
  return Modint(a)+=b;
}
inline Modint operator-(long long a, Modint b){
  return Modint(a)-=b;
}
inline Modint operator*(long long a, Modint b){
  return Modint(a)*=b;
}
inline Modint operator/(long long a, Modint b){
  return Modint(a)/=b;
}
inline int my_getchar(){
  static char buf[1048576];
  static int s = 1048576;
  static int e = 1048576;
  if(s == e && e == 1048576){
    e = fread(buf, 1, 1048576, stdin);
    s = 0;
  }
  if(s == e){
    return EOF;
  }
  return buf[s++];
}
inline void rd(int &x){
  int k;
  int m=0;
  x=0;
  for(;;){
    k = my_getchar();
    if(k=='-'){
      m=1;
      break;
    }
    if('0'<=k&&k<='9'){
      x=k-'0';
      break;
    }
  }
  for(;;){
    k = my_getchar();
    if(k<'0'||k>'9'){
      break;
    }
    x=x*10+k-'0';
  }
  if(m){
    x=-x;
  }
}
inline void rd(long long &x){
  int k;
  int m=0;
  x=0;
  for(;;){
    k = my_getchar();
    if(k=='-'){
      m=1;
      break;
    }
    if('0'<=k&&k<='9'){
      x=k-'0';
      break;
    }
  }
  for(;;){
    k = my_getchar();
    if(k<'0'||k>'9'){
      break;
    }
    x=x*10+k-'0';
  }
  if(m){
    x=-x;
  }
}
inline int rd_int(void){
  int x;
  rd(x);
  return x;
}
struct MY_WRITER{
  char buf[1048576];
  int s;
  int e;
  MY_WRITER(){
    s = 0;
    e = 1048576;
  }
  ~MY_WRITER(){
    if(s){
      fwrite(buf, 1, s, stdout);
    }
  }
}
;
MY_WRITER MY_WRITER_VAR;
void my_putchar(int a){
  if(MY_WRITER_VAR.s == MY_WRITER_VAR.e){
    fwrite(MY_WRITER_VAR.buf, 1, MY_WRITER_VAR.s, stdout);
    MY_WRITER_VAR.s = 0;
  }
  MY_WRITER_VAR.buf[MY_WRITER_VAR.s++] = a;
}
inline void wt_L(char a){
  my_putchar(a);
}
inline void wt_L(int x){
  int s=0;
  int m=0;
  char f[10];
  if(x<0){
    m=1;
    x=-x;
  }
  while(x){
    f[s++]=x%10;
    x/=10;
  }
  if(!s){
    f[s++]=0;
  }
  if(m){
    my_putchar('-');
  }
  while(s--){
    my_putchar(f[s]+'0');
  }
}
inline void wt_L(Modint x){
  int i;
  i = (int)x;
  wt_L(i);
}
template<class S, class T> inline S chmax(S &a, T b){
  if(a<b){
    a=b;
  }
  return a;
}
template<class T> struct Comb{
  int mem_fact;
  T*factri;
  T*ifactri;
  int mem_dfact;
  T*dfactri;
  int mem_pw2;
  int mem_pw3;
  int mem_pw10;
  int mem_rep1;
  T*pw2c;
  T*pw3c;
  T*pw10c;
  T*rep1c;
  int mem_ipw2;
  int mem_ipw3;
  int mem_ipw10;
  T*ipw2c;
  T*ipw3c;
  T*ipw10c;
  Comb(){
    mem_fact = 0;
    mem_dfact = 0;
    mem_pw2 = mem_pw3 = mem_pw10 = mem_rep1 = 0;
    mem_ipw2 = mem_ipw3 = mem_ipw10 = 0;
  }
  inline void expand_fact(int k){
    int i;
    if(k <= mem_fact){
      return;
    }
    chmax(k, 2 * mem_fact);
    if(mem_fact == 0){
      factri = (T*)malloc(k * sizeof(T));
      ifactri = (T*)malloc(k * sizeof(T));
      factri[0] = 1;
      for(i=(1);i<(k);i++){
        factri[i] = i * factri[i-1];
      }
      ifactri[k-1] = 1 / factri[k-1];
      for(i=(k-1)-1;i>=(0);i--){
        ifactri[i] = (i+1) * ifactri[i+1];
      }
    }
    else{
      factri = (T*)realloc(factri, k * sizeof(T));
      ifactri = (T*)realloc(ifactri, k * sizeof(T));
      for(i=(mem_fact);i<(k);i++){
        factri[i] = i * factri[i-1];
      }
      ifactri[k-1] = 1 / factri[k-1];
      for(i=(k-1)-1;i>=(mem_fact);i--){
        ifactri[i] = (i+1) * ifactri[i+1];
      }
    }
    mem_fact = k;
  }
  inline T fac(int k){
    if(mem_fact < k+1){
      expand_fact(k+1);
    }
    return factri[k];
  }
  inline T ifac(int k){
    if(mem_fact < k+1){
      expand_fact(k+1);
    }
    return ifactri[k];
  }
  inline T C(int a, int b){
    if(b < 0 || b > a){
      return 0;
    }
    if(mem_fact < a+1){
      expand_fact(a+1);
    }
    return factri[a] * ifactri[b] * ifactri[a-b];
  }
  inline T P(int a, int b){
    if(b < 0 || b > a){
      return 0;
    }
    if(mem_fact < a+1){
      expand_fact(a+1);
    }
    return factri[a] * ifactri[a-b];
  }
  inline T H(int a, int b){
    if(a==0 && b==0){
      return 1;
    }
    if(a <= 0 || b < 0){
      return 0;
    }
    if(mem_fact < a+b){
      expand_fact(a+b);
    }
    return C(a+b-1, b);
  }
  inline T Multinomial(int sz, int a[]){
    int i;
    int s = 0;
    T res;
    for(i=(0);i<(sz);i++){
      s += a[i];
    }
    if(mem_fact < s+1){
      expand_fact(s+1);
    }
    res = factri[s];
    for(i=(0);i<(sz);i++){
      res *= ifactri[a[i]];
    }
    return res;
  }
  inline T Multinomial(int a){
    return 1;
  }
  inline T Multinomial(int a, int b){
    if(mem_fact < a+b+1){
      expand_fact(a+b+1);
    }
    return factri[a+b] * ifactri[a] * ifactri[b];
  }
  inline T Multinomial(int a, int b, int c){
    if(mem_fact < a+b+c+1){
      expand_fact(a+b+c+1);
    }
    return factri[a+b+c] * ifactri[a] * ifactri[b] * ifactri[c];
  }
  inline T Multinomial(int a, int b, int c, int d){
    if(mem_fact < a+b+c+d+1){
      expand_fact(a+b+c+d+1);
    }
    return factri[a+b+c+d] * ifactri[a] * ifactri[b] * ifactri[c] * ifactri[d];
  }
  inline T Catalan(int n){
    if(n < 0){
      return 0;
    }
    if(mem_fact < 2*n+1){
      expand_fact(2*n+1);
    }
    return factri[2*n] * ifactri[n] * ifactri[n+1];
  }
  inline T C_s(long long a, long long b){
    long long i;
    T res;
    if(b < 0 || b > a){
      return 0;
    }
    if(b > a - b){
      b = a - b;
    }
    res = 1;
    for(i=(0);i<(b);i++){
      res *= a - i;
      res /= i + 1;
    }
    return res;
  }
  inline T P_s(long long a, long long b){
    long long i;
    T res;
    if(b < 0 || b > a){
      return 0;
    }
    res = 1;
    for(i=(0);i<(b);i++){
      res *= a - i;
    }
    return res;
  }
  inline T per_s(long long n, long long k){
    T d;
    int m;
    if(n < 0 || k < 0){
      return 0;
    }
    if(n == k  &&  k == 0){
      return 1;
    }
    if(n == 0 || k == 0){
      return 0;
    }
    if(k==1){
      return 1;
    }
    if(k==2){
      d = n / 2;
      return d;
    }
    if(k==3){
      d = (n-1) / 6;
      m = (n-1) % 6;
      if(m==0){
        return 3 * d * d + d;
      }
      if(m==1){
        return 3 * d * d + 2 * d;
      }
      if(m==2){
        return 3 * d * d + 3 * d + 1;
      }
      if(m==3){
        return 3 * d * d + 4 * d + 1;
      }
      if(m==4){
        return 3 * d * d + 5 * d + 2;
      }
      if(m==5){
        return 3 * d * d + 6 * d + 3;
      }
    }
    assert(0 && "per_s should be k <= 3");
    return -1;
  }
  inline void expand_dfact(int k){
    int i;
    if(k <= mem_dfact){
      return;
    }
    chmax(k, 3);
    chmax(k, 2 * mem_dfact);
    if(mem_dfact==0){
      dfactri = (T*)malloc(k * sizeof(T));
      dfactri[0] = dfactri[1] = 1;
      for(i=(2);i<(k);i++){
        dfactri[i] = i * dfactri[i-2];
      }
    }
    else{
      dfactri = (T*)realloc(dfactri, k * sizeof(T));
      for(i=(mem_dfact);i<(k);i++){
        dfactri[i] = i * dfactri[i-2];
      }
    }
    mem_dfact = k;
  }
  inline void expand_pw2(int k){
    int i;
    if(k <= mem_pw2){
      return;
    }
    chmax(k, 2 * mem_pw2);
    if(mem_pw2==0){
      pw2c = (T*)malloc(k * sizeof(T));
      pw2c[0] = 1;
      for(i=(1);i<(k);i++){
        pw2c[i] = 2 * pw2c[i-1];
      }
    }
    else{
      pw2c = (T*)realloc(pw2c, k * sizeof(T));
      for(i=(mem_pw2);i<(k);i++){
        pw2c[i] = 2 * pw2c[i-1];
      }
    }
    mem_pw2 = k;
  }
  inline void expand_ipw2(int k){
    int i;
    if(k <= mem_ipw2){
      return;
    }
    chmax(k, 2);
    chmax(k, 2 * mem_ipw2);
    if(mem_ipw2==0){
      ipw2c = (T*)malloc(k * sizeof(T));
      ipw2c[0] = 1;
      ipw2c[1] = ipw2c[0] / 2;
      for(i=(1);i<(k);i++){
        ipw2c[i] = ipw2c[1] * ipw2c[i-1];
      }
    }
    else{
      ipw2c = (T*)realloc(ipw2c, k * sizeof(T));
      for(i=(mem_ipw2);i<(k);i++){
        ipw2c[i] = ipw2c[1] * ipw2c[i-1];
      }
    }
    mem_ipw2 = k;
  }
  inline void expand_pw3(int k){
    int i;
    if(k <= mem_pw3){
      return;
    }
    chmax(k, 2 * mem_pw3);
    if(mem_pw3==0){
      pw3c = (T*)malloc(k * sizeof(T));
      pw3c[0] = 1;
      for(i=(1);i<(k);i++){
        pw3c[i] = 3 * pw3c[i-1];
      }
    }
    else{
      pw3c = (T*)realloc(pw3c, k * sizeof(T));
      for(i=(mem_pw3);i<(k);i++){
        pw3c[i] = 3 * pw3c[i-1];
      }
    }
    mem_pw3 = k;
  }
  inline void expand_ipw3(int k){
    int i;
    if(k <= mem_ipw3){
      return;
    }
    chmax(k, 2);
    chmax(k, 2 * mem_ipw3);
    if(mem_ipw3==0){
      ipw3c = (T*)malloc(k * sizeof(T));
      ipw3c[0] = 1;
      ipw3c[1] = ipw3c[0] / 3;
      for(i=(1);i<(k);i++){
        ipw3c[i] = ipw3c[1] * ipw3c[i-1];
      }
    }
    else{
      ipw3c = (T*)realloc(ipw3c, k * sizeof(T));
      for(i=(mem_ipw3);i<(k);i++){
        ipw3c[i] = ipw3c[1] * ipw3c[i-1];
      }
    }
    mem_ipw3 = k;
  }
  inline void expand_pw10(int k){
    int i;
    if(k <= mem_pw10){
      return;
    }
    chmax(k, 2 * mem_pw10);
    if(mem_pw10==0){
      pw10c = (T*)malloc(k * sizeof(T));
      pw10c[0] = 1;
      for(i=(1);i<(k);i++){
        pw10c[i] = 10 * pw10c[i-1];
      }
    }
    else{
      pw10c = (T*)realloc(pw10c, k * sizeof(T));
      for(i=(mem_pw10);i<(k);i++){
        pw10c[i] = 10 * pw10c[i-1];
      }
    }
    mem_pw10 = k;
  }
  inline void expand_ipw10(int k){
    int i;
    if(k <= mem_ipw10){
      return;
    }
    chmax(k, 2);
    chmax(k, 2 * mem_ipw10);
    if(mem_ipw10==0){
      ipw10c = (T*)malloc(k * sizeof(T));
      ipw10c[0] = 1;
      ipw10c[1] = ipw10c[0] / 10;
      for(i=(1);i<(k);i++){
        ipw10c[i] = ipw10c[1] * ipw10c[i-1];
      }
    }
    else{
      ipw10c = (T*)realloc(ipw10c, k * sizeof(T));
      for(i=(mem_ipw10);i<(k);i++){
        ipw10c[i] = ipw10c[1] * ipw10c[i-1];
      }
    }
    mem_ipw10 = k;
  }
  inline void expand_rep1(int k){
    int i;
    if(k <= mem_rep1){
      return;
    }
    chmax(k, 2 * mem_rep1);
    if(mem_rep1==0){
      rep1c = (T*)malloc(k * sizeof(T));
      rep1c[0] = 0;
      for(i=(1);i<(k);i++){
        rep1c[i] = 10 * rep1c[i-1] + 1;
      }
    }
    else{
      rep1c = (T*)realloc(rep1c, k * sizeof(T));
      for(i=(mem_rep1);i<(k);i++){
        rep1c[i] = 10 * rep1c[i-1] + 1;
      }
    }
    mem_rep1 = k;
  }
  inline T dfac(int k){
    if(k >= 0){
      if(mem_dfact < k+1){
        expand_dfact(k+1);
      }
      return dfactri[k];
    }
    if(k==-1){
      return 1;
    }
    k = - k - 2;
    if(k % 4 == 1){
      return 1 / (-dfac(k));
    }
    return 1 / dfac(k);
  }
  inline T pw2(int k){
    if(k >= 0){
      if(mem_pw2 < k+1){
        expand_pw2(k+1);
      }
      return pw2c[k];
    }
    else{
      k = -k;
      if(mem_ipw2 < k+1){
        expand_ipw2(k+1);
      }
      return ipw2c[k];
    }
  }
  inline T pw3(int k){
    if(k >= 0){
      if(mem_pw3 < k+1){
        expand_pw3(k+1);
      }
      return pw3c[k];
    }
    else{
      k = -k;
      if(mem_ipw3 < k+1){
        expand_ipw3(k+1);
      }
      return ipw3c[k];
    }
  }
  inline T pw10(int k){
    if(k >= 0){
      if(mem_pw10 < k+1){
        expand_pw10(k+1);
      }
      return pw10c[k];
    }
    else{
      k = -k;
      if(mem_ipw10 < k+1){
        expand_ipw10(k+1);
      }
      return ipw10c[k];
    }
  }
  inline T repunit(int k){
    if(mem_rep1 < k+1){
      expand_rep1(k+1);
    }
    return rep1c[k];
  }
}
;
template<> inline Modint Comb<Modint>::C_s(long long a, long long b){
  long long i;
  Modint res;
  Modint d;
  if(b < 0 || b > a){
    return 0;
  }
  if(b > a - b){
    b = a - b;
  }
  res = d = 1;
  for(i=(0);i<(b);i++){
    res *= a - i;
    d *= i + 1;
  }
  return res / d;
}
Comb<Modint> c;
int main(){
  int Lj4PdHRW;
  wmem = memarr;
  int KL2GvlyY = rd_int();
  for(Lj4PdHRW=(0);Lj4PdHRW<(KL2GvlyY);Lj4PdHRW++){
    int i;
    long long N;
    rd(N);
    long long K;
    rd(K);
    long long chk;
    Modint res = 1;
    Modint tmp = 1;
    Modint cur;
    for(i=(1);i<(N+1);i++){
      chk = N - (K-1) * (i-1);
      if(chk < 0){
        break;
      }
      cur = c.C(chk, i) / c.C(N, i);
      res += cur;
      tmp = cur;
    }
    wt_L(res);
    wt_L('\n');
  }
  return 0;
}
// cLay version 20210529-1 [beta]

// --- original code ---
// //no-unlocked
// Comb<Modint> c;
// {
//   REP(rd_int()){
//     ll @N, @K, chk;
//     Modint res = 1, tmp = 1, cur;
//     rep(i,1,N+1){
//       chk = N - (K-1) * (i-1);
//       if(chk < 0) break;
//       cur = c.C(chk, i) / c.C(N, i);
//       res += cur;
//       tmp = cur;
//     }
//     wt(res);
//   }
// }