description: Theofanis really likes sequences of positive integers, thus his teacher (Yeltsa Kcir) gave him a problem about a sequence that consists of only special numbers.
  
  Let's call a positive number special if it can be written as a sum of different non-negative powers of n. For example, for n = 4 number 17 is special, because it can be written as 4^0 + 4^2 = 1 + 16 = 17, but 9 is not.
  
  Theofanis asks you to help him find the k-th special number if they are sorted in increasing order. Since this number may be too large, output it modulo 10^9+7.
  
  Input
  
  The first line contains a single integer t (1 ≤ t ≤ 10^4) — the number of test cases.
  
  The first and only line of each test case contains two integers n and k (2 ≤ n ≤ 10^9; 1 ≤ k ≤ 10^9).
  
  Output
  
  For each test case, print one integer — the k-th special number in increasing order modulo 10^9+7.
  
  Example
  
  Input
  
  
  3
  3 4
  2 12
  105 564
  
  
  Output
  
  
  9
  12
  3595374
  
  Note
  
  For n = 3 the sequence is [1,3,4,9...]
solution: import java.util.*;
  import java.io.*;
  public class Main {
  		static long mod = 1000000007;
  		static PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out));
  		public static void main(String[] args) throws IOException  {
  			FastReader sc = new FastReader();
  			int t = sc.nextInt();
  			while( t-- > 0) {
  				int n = sc.nextInt();
  				int k = sc.nextInt();
  				String input = Integer.toBinaryString(k);
  				long ans = 0;
  			//	out.println(input);
  				int count = 0;
  				for( int i = input.length()-1 ; i>=0; i--) {
  					count++;
  					if( input.charAt(i) == '1') {
  					//	out.println(count);
  						long temp = 1L;
  						for( int j = 0 ;j < count-1 ;j++) {
  							temp*=n;
  							temp%=mod;
  						}
  						ans+=temp;
  						ans%=mod;
  					}
  				}
  				out.println(ans);
  			}
  			out.flush();
  		}
  		
  		public static boolean ifpowof2(long n ) {
  			return ((n&(n-1)) == 0);
  		}
  		
  		public static int[] nextLargerElement(int[] arr, int n)	{ 
  			Stack<Integer> stack = new Stack<>();
  			int rtrn[] = new int[n];
  			rtrn[n-1] = -1;
  	        stack.push( n-1);
  	        for( int i = n-2 ;i >= 0 ; i--){
  	            int temp = arr[i];
  	            int lol = -1;
  	            while( !stack.isEmpty() && arr[stack.peek()] <= temp){
  	            	if(arr[stack.peek()] == temp ) {
  	            		lol = stack.peek();
  	            	}
  	                stack.pop();
  	            }
  	            if( stack.isEmpty()){
  	            	if( lol != -1) {
  	            		rtrn[i] = lol;
  	            	}
  	            	else {
  	            		rtrn[i] = -1;
  	            	}
  	            }
  	            else{
  	            	rtrn[i] = stack.peek();
  	            }
  	            stack.push( i);
  	        }
  	        return rtrn;
  		}
  		
  		static int gcd(int a, int b)
  		{
  			if (a == 0)
  				return b;
  			return gcd(b % a, a);
  		}
  		
  			   
  		 static int lcm(int a, int b)
  		 {
  			 return (a / gcd(a, b)) * b;
  		 }
  		 
  
  		 static long rightmostsetbit(long n) {
  			 return n&-n;
  		 }
  		 
  		 static long leftmostsetbit(long n)
  		    {
  		        long k = (long)(Math.log(n) / Math.log(2));
  		        return 1 << k;
  		    }
  	 
  		 static HashMap<Long,Long> primefactor( long n){
  			 HashMap<Long ,Long> hm = new HashMap<>();
  			 long temp = 0;
  			 while( n%2 == 0) {
  				 temp++;
  				 n/=2;
  			 }	
  			 if( temp!= 0) {
  				 hm.put( 2L, temp);
  			 }
  			 long c = (long)Math.sqrt(n);
  			 for( long i = 3 ; i <= c ; i+=2) {
  				 temp = 0;
  				 while( n% i == 0) {
  					 temp++;
  					 n/=i;
  				 }
  				 if( temp!= 0) {
  					 hm.put( i, temp);
  				 }
  	 		 }
  	 		 if( n!= 1) {
  	 			 hm.put( n , 1L);
  	 		 }
  	 		 return hm;	
  		 }
  	 
  		 static class FastReader {
  			 BufferedReader br;
  			 StringTokenizer st;
  		 
  			 public FastReader()
  			 {
  				 br = new BufferedReader(new InputStreamReader(System.in));
  			 }
  		        
  			 String next()
  			 {
  				 while (st == null || !st.hasMoreElements()) {
  					 try {
  						 st = new StringTokenizer(br.readLine());
  					 }
  					 catch (IOException e) {
  						 e.printStackTrace();
  					 }
  				 }
  				 return st.nextToken();
  			 }
  		 
  			 int nextInt() { return Integer.parseInt(next()); }
  			 
  			 long nextLong() { return Long.parseLong(next()); }
  			 
  			 double nextDouble()
  			 {
  				 return Double.parseDouble(next());
  			 }	
  		 
  			 String nextLine()
  			 {
  				 String str = "";
  				 try {
  					 str = br.readLine();
  				 }
  				 catch (IOException e) {
  					 e.printStackTrace();
  				 }
  				 return str;
  			 }
  		 }	
  }