Due to the coronavirus pandemic, city authorities obligated citizens to keep a social distance. The mayor of the city Semyon wants to light up Gluharniki park so that people could see each other even at night to keep the social distance.

The park is a rectangular table with n rows and m columns, where the cells of the table are squares, and the boundaries between the cells are streets. External borders are also streets. Every street has length 1. For example, park with n=m=2 has 12 streets.

You were assigned to develop a plan for lighting the park. You can put lanterns in the middle of the streets. The lamp lights two squares near it (or only one square if it stands on the border of the park).

<image> The park sizes are: n=4, m=5. The lighted squares are marked yellow. Please note that all streets have length 1. Lanterns are placed in the middle of the streets. In the picture not all the squares are lit.

Semyon wants to spend the least possible amount of money on lighting but also wants people throughout the park to keep a social distance. So he asks you to find the minimum number of lanterns that are required to light all the squares.

Input

The first line contains a single integer t (1 ≤ t ≤ 10^4) — the number of test cases in the input. Then t test cases follow.

Each test case is a line containing two integers n, m (1 ≤ n, m ≤ 10^4) — park sizes.

Output

Print t answers to the test cases. Each answer must be a single integer — the minimum number of lanterns that are required to light all the squares.

Example

Input


5
1 1
1 3
2 2
3 3
5 3


Output


1
2
2
5
8

Note

Possible optimal arrangement of the lanterns for the 2-nd test case of input data example: <image>

Possible optimal arrangement of the lanterns for the 3-rd test case of input data example: <image>
import java.io.*;
import java.util.*;
import java.math.*;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class ParkLighting {
    public static void main(String[] args) throws IOException {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskA solver = new TaskA();
        solver.solve(in.nextInt(), in, out);
        out.close();
    }
    static class TaskA {
        long mod = (long)1e9 + 7;
        public void solve(int testNumber, InputReader in, PrintWriter out) throws IOException {
            while(testNumber-->0){
            	int n = in.nextInt();
            	int m = in.nextInt();
            	if(n%2==0 || m%2==0){
            		out.println(n*m/2);
            	}
            	else{
            		out.println(n/2*m + (m+1)/2);
            	}
            }
        }
        public void print1d(long a[] , PrintWriter out){
        	for(int i=0;i<a.length;i++)
        		out.print(a[i] + " ");
        	out.println();
        }
        public void print2d(int a[][] , PrintWriter out){
            for(int i=0;i<a.length;i++){
                for(int j=0;j<a[i].length;j++)
                    out.print(a[i][j]);
                out.println();
            }
            // out.println();
        }
        public void sieve(int a[]){
            a[0] = a[1] = 1;
            int i;
            for(i=2;i*i<=a.length;i++){
                if(a[i] != 0)
                    continue;
                a[i] = i;
                for(int k = (i)*(i);k<a.length;k+=i){
                    if(a[k] != 0)
                        continue;
                    a[k] = i;
                }
            }
        }
        public int [][] matrixExpo(int c[][] , int n){
            int a[][] = new int[c.length][c[0].length];
            int b[][] = new int[a.length][a[0].length];
            for(int i=0;i<c.length;i++)
                for(int j=0;j<c[0].length;j++)
                    a[i][j] = c[i][j];
            for(int i=0;i<a.length;i++)
                b[i][i] = 1;
            while(n!=1){
                if(n%2 == 1){
                    b = matrixMultiply(a , a);
                    n--;
                }
                a = matrixMultiply(a , a);
                n/=2;
            }
            return matrixMultiply(a , b);
        }
        public int [][] matrixMultiply(int a[][] , int b[][]){
            int r1 = a.length;
            int c1 = a[0].length;
            int c2 = b[0].length;
            int c[][] = new int[r1][c2];
            for(int i=0;i<r1;i++){
                for(int j=0;j<c2;j++){
                    for(int k=0;k<c1;k++)
                        c[i][j] += a[i][k]*b[k][j];
                }
            }
            return c;
        }
        public long nCrPFermet(int n , int r , long p){
            if(r==0)
                return 1l;
            long fact[] = new long[n+1];
            fact[0] = 1;
            for(int i=1;i<=n;i++)
                fact[i] = (i*fact[i-1])%p;
            long modInverseR = pow(fact[r] , p-2 , p);
            long modInverseNR = pow(fact[n-r] , p-2 , p);
            long w = (((fact[n]*modInverseR)%p)*modInverseNR)%p;
            return w;
        }
        public long pow(long a, long b, long m) {
            a %= m;
            long res = 1;
            while (b > 0) {
                long x = b&1;
                if (x == 1)
                    res = res * a % m;
                a = a * a % m;
                b >>= 1;
            }
            return res;
        }
        public long pow(long a, long b) {
            long res = 1;
            while (b > 0) {
                long x = b&1;
                if (x == 1)
                    res = res * a;
                a = a * a;
                b >>= 1;
            }
            return res;
        }
        public void swap(int a[] , int p1 , int p2){
            int x = a[p1];
            a[p1] = a[p2];
            a[p2] = x;
        }
        public void sortedArrayToBST(TreeSet<Integer> a , int start, int end) { 
            if (start > end) {
                return;
            }
            int mid = (start + end) / 2;
            a.add(mid);
            sortedArrayToBST(a, start, mid - 1);
            sortedArrayToBST(a, mid + 1, end); 
        }
        class Combine{
            int value;
            int delete;
            Combine(int val , int delete){
                this.value = val;
                this.delete = delete;
            }
        }
        class Sort2 implements Comparator<Combine>{
            public int compare(Combine a , Combine b){
                if(a.value > b.value)
                    return 1;
                else if(a.value == b.value && a.delete>b.delete)
                    return 1;
                else if(a.value == b.value && a.delete == b.delete)
                    return 0;
                return -1;
            }
        }
        public int lowerLastBound(ArrayList<Integer> a , int x){
            int l = 0;
            int r = a.size()-1;
            if(a.get(l)>=x)
                return -1;
            if(a.get(r)<x)
                return r;
            int mid = -1;
            while(l<=r){
                mid = (l+r)/2;
                if(a.get(mid) == x && a.get(mid-1)<x)
                    return mid-1;
                else if(a.get(mid)>=x)
                    r = mid-1;
                else if(a.get(mid)<x && a.get(mid+1)>=x)
                    return mid;
                else if(a.get(mid)<x && a.get(mid+1)<x)
                    l = mid+1;
            }
            return mid;
        }
        public int upperFirstBound(ArrayList<Integer> a , Integer x){
            int l = 0;
            int r = a.size()-1;
            if(a.get(l)>x)
                return l;
            if(a.get(r)<=x)
                return r+1;
            int mid = -1;
            while(l<=r){
                mid = (l+r)/2;
                if(a.get(mid) == x && a.get(mid+1)>x)
                    return mid+1;
                else if(a.get(mid)<=x)
                    l = mid+1;
                else if(a.get(mid)>x && a.get(mid-1)<=x)
                    return mid;
                else if(a.get(mid)>x && a.get(mid-1)>x)
                    r = mid-1;
            }
            return mid;
        }
        public int lowerLastBound(int a[] , int x){
            int l = 0;
            int r = a.length-1;
            if(a[l]>=x)
                return -1;
            if(a[r]<x)
                return r;
            int mid = -1;
            while(l<=r){
                mid = (l+r)/2;
                if(a[mid] == x && a[mid-1]<x)
                    return mid-1;
                else if(a[mid]>=x)
                    r = mid-1;
                else if(a[mid]<x && a[mid+1]>=x)
                    return mid;
                else if(a[mid]<x && a[mid+1]<x)
                    l = mid+1;
            }
            return mid;
        }
        public int upperFirstBound(int a[] , int x){
            int l = 0;
            int r = a.length-1;
            if(a[l]>x)
                return l;
            if(a[r]<=x)
                return r+1;
            int mid = -1;
            while(l<=r){
                mid = (l+r)/2;
                if(a[mid] == x && a[mid+1]>x)
                    return mid+1;
                else if(a[mid]<=x)
                    l = mid+1;
                else if(a[mid]>x && a[mid-1]<=x)
                    return mid;
                else if(a[mid]>x && a[mid-1]>x)
                    r = mid-1;
            }
            return mid;
        }
        public long log(float number , int base){
            return (long) Math.floor((Math.log(number) / Math.log(base)));
        }
        public long gcd(long a , long b){
            if(a<b){
                long c = b;
                b = a;
                a = c;
            }
            if(b == 0)
                return a;
            return gcd(b , a%b);
        }
        public long[] gcdEx(long p, long q) {
            if (q == 0)
                return new long[] { p, 1, 0 };
            long[] vals = gcdEx(q, p % q);
            long d = vals[0];
            long a = vals[2];
            long b = vals[1] - (p / q) * vals[2];
            // 0->gcd 1->xValue 2->yValue
            return new long[] { d, a, b };
        }
        public void sievePhi(int a[]){
            a[0] = 0;
            a[1] = 1;
            for(int i=2;i<a.length;i++)
                a[i] = i-1;
            for(int i=2;i<a.length;i++)
                for(int j = 2*i;j<a.length;j+=i)
                    a[j] -= a[i];
        }
        public void lcmSum(long a[]){
        	int sievePhi[] = new int[(int)1e6 + 1];
        	sievePhi(sievePhi);
        	a[0] = 0;
        	for(int i=1;i<a.length;i++)
        		for(int j = i;j<a.length;j+=i)
        			a[j] += (long)i*sievePhi[i];
        }
        static class AVLTree{
            Node root;
            public AVLTree(){
                this.root = null;
            }
            public int height(Node n){
                return (n == null ? 0 : n.height);
            }
            public int getBalance(Node n){
                return (n == null ? 0 : height(n.left) - height(n.right));
            }
            public Node rotateRight(Node a){
                Node b = a.left;
                Node br = b.right;

                a.lSum -= b.lSum;
                a.lCount -= b.lCount;
                
                b.rSum += a.rSum;
                b.rCount += a.rCount;
                
                b.right = a;
                a.left = br;
                
                a.height = 1 + Math.max(height(a.left) , height(a.right));
                b.height = 1 + Math.max(height(b.left) , height(b.right));
                return b;
            }
            public Node rotateLeft(Node a){
                Node b = a.right;
                Node bl = b.left;
                
                a.rSum -= b.rSum;
                a.rCount -= b.rCount;
                
                b.lSum += a.lSum;
                b.lCount += a.lCount;
                
                b.left = a;
                a.right = bl;
                
                a.height = 1 + Math.max(height(a.left) , height(a.right));
                b.height = 1 + Math.max(height(b.left) , height(b.right));
                return b;
            }
            public Node insert(Node root , long value){
                if(root == null){
                    return new Node(value);
                }
                if(value<=root.value){
                    root.lCount++;
                    root.lSum += value;
                    root.left =  insert(root.left , value);
                }
                if(value>root.value){
                    root.rCount++;
                    root.rSum += value;
                    root.right = insert(root.right , value);
                }
                // updating the height of the root
                root.height = 1 + Math.max(height(root.left) , height(root.right));
                int balance = getBalance(root);

                //ll
                if(balance>1 && value<=root.left.value)
                    return rotateRight(root);
                //rr
                if(balance<-1 && value>root.right.value)
                    return rotateLeft(root);
                //lr
                if(balance>1 && value>root.left.value){
                    root.left = rotateLeft(root.left);
                    return rotateRight(root);
                }
                //rl
                if(balance<-1 && value<=root.right.value){
                    root.right = rotateRight(root.right);
                    return rotateLeft(root);
                }
                return root;
            }
            public void insertElement(long value){
                this.root = insert(root , value);
            }
            public int getElementLessThanK(long k){
                int count = 0;
                Node temp = root;
                while(temp!=null){
                    if(temp.value == k){
                        if(temp.left == null || temp.left.value<k){
                            count += temp.lCount;
                            return count-1;
                        }
                        else
                            temp = temp.left;
                    }
                    else if(temp.value>k){
                        temp = temp.left;
                    }
                    else{
                        count += temp.lCount;
                        temp = temp.right;
                    }
                }
                return count;
            }
            public void inorder(Node root , PrintWriter out){
                Node temp = root;
                if(temp!=null){
                    inorder(temp.left , out);
                    out.println(temp.value + " " + temp.lCount + " " + temp.rCount);
                    inorder(temp.right , out);
                }
            }
        }
        static class Node{
            long value;
            long lCount , rCount;
            long lSum , rSum;
            Node left , right;
            int height;
            public Node(long value){
                this.value = value;
                left = null;
                right = null;
                lCount = 1;
                rCount = 1;
                lSum = value;
                rSum = value;
                height = 1;
            }
        }
    }

    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

        public long nextLong() {
            return Long.parseLong(next());
        }

    }
}
