Misha and Vanya have played several table tennis sets. Each set consists of several serves, each serve is won by one of the players, he receives one point and the loser receives nothing. Once one of the players scores exactly k points, the score is reset and a new set begins.

Across all the sets Misha scored a points in total, and Vanya scored b points. Given this information, determine the maximum number of sets they could have played, or that the situation is impossible.

Note that the game consisted of several complete sets.

Input

The first line contains three space-separated integers k, a and b (1 ≤ k ≤ 109, 0 ≤ a, b ≤ 109, a + b > 0).

Output

If the situation is impossible, print a single number -1. Otherwise, print the maximum possible number of sets.

Examples

Input

11 11 5


Output

1


Input

11 2 3


Output

-1

Note

Note that the rules of the game in this problem differ from the real table tennis game, for example, the rule of "balance" (the winning player has to be at least two points ahead to win a set) has no power within the present problem.
import java.io.*;
import java.util.*;
public class vcx {
	public static void main(String args[]){
		int k=i(),a=i(),b=i();
		int s=0;
		if(a>=k && b>=k)
		{
			s=a/k+b/k;
			out.println(s);
		}
		else if(a>=k || b>=k )
		{
			if(a>=k)
			{
				
			
			if(a%k==0)
			{
				out.println(a/k);
			}
			else
			{
				out.println(-1);
			}
			}else
			{
				if(b%k==0)
				{
					out.println(b/k);
				}
				else
				{
					out.println(-1);
				}
			}
		}
		else
		{
			out.println(-1);
		}
		out.close();
	}
static InputReader in = new InputReader(System.in);
    static OutputWriter out = new OutputWriter(System.out);
    
    static int i()
    {
    	return in.readInt();
    }
    
    static long l()
    {
    	return in.readLong();
    }
    
    static double d()
    {
    	return in.readDouble();
    }
    
    static String s()
    {
    	return in.readString();
    }
    
    static void Iarr( int[] array, int no )
    {
    	for( int i=0 ; i<no ; i++ )
    	{
    		array[i] = i(); 
    	}
    }
    
    static void Larr( long[] array, int no )
    {
    	for( int i=0 ; i<no ; i++ )
    	{
    		array[i] = l(); 
    	}
    }
    
    static void Darr( double[] array, int no )
    {
    	for( int i=0 ; i<no ; i++ )
    	{
    		array[i] = d(); 
    	}
    }
    
    static void Sarr( String[] array, int no )
    {
    	for( int i=0 ; i<no ; i++ )
    	{
    		array[i] = s(); 
    	}
    }
    
    private static class InputReader
    {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private SpaceCharFilter filter;
 
        public InputReader(InputStream stream)
        {
            this.stream = stream;
        }
 
        
        
        
        
        
        
        public int read()
        {
            if (numChars == -1)
                throw new InputMismatchException();
            if (curChar >= numChars)
            {
                curChar = 0;
                try
                {
                    numChars = stream.read(buf);
                } catch (IOException e)
                {
                    throw new InputMismatchException();
                }
                if (numChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }
 
        public int readInt()
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-')
            {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do
            {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }
 
        public String readString()
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuilder res = new StringBuilder();
            do
            {
                res.appendCodePoint(c);
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }
        public double readDouble() {
            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, readInt());
                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, readInt());
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    m /= 10;
                    res += (c - '0') * m;
                    c = read();
                }
            }
            return res * sgn;
        }
        public long readLong() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            long res = 0;
            do {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }
        public boolean isSpaceChar(int c)
        {
            if (filter != null)
                return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }
 
        public String next()
        {
            return readString();
        }
 
        public interface SpaceCharFilter
        {
            public boolean isSpaceChar(int ch);
        }
    }
 
    private static class OutputWriter
    {
        private final PrintWriter writer;
 
        public OutputWriter(OutputStream outputStream)
        {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }
 
        public OutputWriter(Writer writer)
        {
            this.writer = new PrintWriter(writer);
        }
 
        public void print(Object... objects)
        {
            for (int i = 0; i < objects.length; i++)
            {
                if (i != 0)
                    writer.print(' ');
                writer.print(objects[i]);
            }
        }
 
        public void println(Object... objects)
        {
            print(objects);
            writer.println();
        }
 
        public void close()
        {
            writer.close();
        }
 
        public void flush()
        {
            writer.flush();
        }
     }
}
