You are given a chessboard of size n × n. It is filled with numbers from 1 to n^2 in the following way: the first ⌈ (n^2)/(2) ⌉ numbers from 1 to ⌈ (n^2)/(2) ⌉ are written in the cells with even sum of coordinates from left to right from top to bottom. The rest n^2 - ⌈ (n^2)/(2) ⌉ numbers from ⌈ (n^2)/(2) ⌉ + 1 to n^2 are written in the cells with odd sum of coordinates from left to right from top to bottom. The operation ⌈x/y⌉ means division x by y rounded up.

For example, the left board on the following picture is the chessboard which is given for n=4 and the right board is the chessboard which is given for n=5.

<image>

You are given q queries. The i-th query is described as a pair x_i, y_i. The answer to the i-th query is the number written in the cell x_i, y_i (x_i is the row, y_i is the column). Rows and columns are numbered from 1 to n.

Input

The first line contains two integers n and q (1 ≤ n ≤ 10^9, 1 ≤ q ≤ 10^5) — the size of the board and the number of queries.

The next q lines contain two integers each. The i-th line contains two integers x_i, y_i (1 ≤ x_i, y_i ≤ n) — description of the i-th query.

Output

For each query from 1 to q print the answer to this query. The answer to the i-th query is the number written in the cell x_i, y_i (x_i is the row, y_i is the column). Rows and columns are numbered from 1 to n. Queries are numbered from 1 to q in order of the input.

Examples

Input

4 5
1 1
4 4
4 3
3 2
2 4


Output

1
8
16
13
4


Input

5 4
2 1
4 2
3 3
3 4


Output

16
9
7
20

Note

Answers to the queries from examples are on the board in the picture from the problem statement.
//package math_codet;

import java.io.*;
import java.util.*;
import java.math.*;
 /******************************************
*    AUTHOR:         AMAN KUMAR SINGH        *
*    INSTITUITION:   KALYANI GOVERNMENT ENGINEERING COLLEGE  *
******************************************/
public class lets_do {
    InputReader in;
    PrintWriter out;
    Helper_class h;
    final long mod=1000000007;
    final int N=200005;
    int MAX_Ai=100005;
    public static void main(String[] args) throws java.lang.Exception{
        new lets_do().run();
    }
    void run() throws Exception{
        in=new InputReader(System.in);
        out = new PrintWriter(System.out);
        h = new Helper_class();
        int t=1;
        while(t-->0){
            solve();
        }
        out.flush();    
        out.close();
    }
    void solve(){
        long n=h.nl();
        int q=h.ni();
        while(q-->0){
            long i=h.nl();
            long j=h.nl();
            long ans=0;
            if(n%2==0){
                if((i+j)%2==0){
                    long placed=(i-1)*(n/2);
                    if(i%2!=0)
                        ans=placed+(j+1)/2;
                    else
                        ans=placed+(j/2);
                }
                else{
                    ans=(n*n)/2;
                    long placed=(i-1)*(n/2);
                    if(i%2==0)
                        ans+=placed+(j+1)/2;
                    else
                        ans+=placed+(j/2);
                }
            }
            else{
                if((i+j)%2==0){
                    long placed=0;
                    if(i%2!=0){
                    	placed=(n*(i-1))/2;
                        ans=placed+(j+1)/2;
                    }
                    else{
                    	long x=(long)(Math.ceil((double)(i-1)/2)*Math.ceil((double)n/2));
                        long xx=(i-1)/2;
                        xx*=n/2;
                        placed=x+xx;
                        //h.pn(x+" "+xx);
                        ans=placed+(j/2);
                    }
                }
                else{
                    ans=(n*n)/2+1;
                    long placed=0;
                    //h.pn(ans);;
                    if(i%2!=0){
                        placed=(n*(i-1))/2;
                        ans+=placed+(j+1)/2;
                    }
                    else{
                    	long x=(long)(Math.ceil((double)(i-1)/2)*Math.ceil((double)n/2));
                        long xx=(i-1)/2;
                        xx*=n/2;
                        placed=x+xx;
                        //h.pn(placed+" "+x+" "+xx);
                        ans+=placed+(j/2);
                    }
                }
            }
            h.pn(ans);
        }
        
    }
    final Comparator<Entity> com=new Comparator<Entity>(){
        public int compare(Entity x, Entity y){
            int xx=Integer.compare(y.a,x.a);
            if(xx==0)
                return Integer.compare(x.a,y.a);
            else
                return xx;
        }
    };
    class Entity{
        int a;
        int b;
        Entity(int p, int q){
            a=p;
            b=q;
        }
    }
    

    class Helper_class{
        long gcd(long a, long b){return (b==0)?a:gcd(b,a%b);}
        int gcd(int a, int b){return (b==0)?a:gcd(b,a%b);}
        long gcd1(long a, long b){return (b==0)?a:gcd(b,a%b);}
        int bitcount(long n){return (n==0)?0:(1+bitcount(n&(n-1)));}
        void p(Object o){out.print(o);}
        void pn(Object o){out.println(o);}
        void pni(Object o){out.println(o);out.flush();}
        String n(){return in.next();}
        String nln(){return in.nextLine();}
        int ni(){return in.nextInt();}
        long nl(){return in.nextLong();}
        double nd(){return in.nextDouble();}

        long mul(long a,long b){
            if(a>=mod)a%=mod;
            if(b>=mod)b%=mod;
            a*=b;
            if(a>=mod)a%=mod;
            return a;
        }
        long modPow(long a, long p){
            long o = 1;
            while(p>0){
                if((p&1)==1)o = mul(o,a);
                a = mul(a,a);
                p>>=1;
            }
            return o;
        }
        long add(long a, long b){
            if(a>=mod)a%=mod;
            if(b>=mod)b%=mod;
            if(b<0)b+=mod;
            a+=b;
            if(a>=mod)a-=mod;
            return a;
        }
    }

    class InputReader{
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
 
        public InputReader(InputStream stream) {
            this.stream = stream;
        }
 
        public int read() {
            if (numChars == -1)
                throw new UnknownError();
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new UnknownError();
                }
                if (numChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }
 
        public int peek() {
            if (numChars == -1)
                return -1;
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    return -1;
                }
                if (numChars <= 0)
                    return -1;
            }
            return buf[curChar];
        }
 
        public void skip(int x) {
            while (x-- > 0)
                read();
        }
 
        public int nextInt() {
            return Integer.parseInt(next());
        }
 
        public long nextLong() {
            return Long.parseLong(next());
        }
 
        public String nextString() {
            return next();
        }
 
        public String next() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuffer res = new StringBuffer();
            do {
                res.appendCodePoint(c);
                c = read();
            } while (!isSpaceChar(c));
 
            return res.toString();
        }
 
        public String nextLine() {
            StringBuffer buf = new StringBuffer();
            int c = read();
            while (c != '\n' && c != -1) {
                if (c != '\r')
                    buf.appendCodePoint(c);
                c = read();
            }
            return buf.toString();
        }
 
        public double nextDouble() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            double res = 0;
            while (!isSpaceChar(c) && c != '.') {
                if (c == 'e' || c == 'E')
                    return res * Math.pow(10, nextInt());
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            if (c == '.') {
                c = read();
                double m = 1;
                while (!isSpaceChar(c)) {
                    if (c == 'e' || c == 'E')
                        return res * Math.pow(10, nextInt());
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    m /= 10;
                    res += (c - '0') * m;
                    c = read();
                }
            }
            return res * sgn;
        }
 
        public boolean hasNext() {
            int value;
            while (isSpaceChar(value = peek()) && value != -1)
                read();
            return value != -1;
        }
 
        private boolean isSpaceChar(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }
    }
}