import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.util.Stack;
							public class Main implements Runnable
							{
								static final long MOD = 1000000007L;
								static final long MOD2 = 1000000009L;
								static class InputReader
								{
									private InputStream stream;
									private byte[] buf = new byte[1024];
									private int curChar;
									private int numChars;
									private SpaceCharFilter filter;
									private BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
							 
									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 String nextLine()
									{
										String str = "";
							            try
							            {
							                str = br.readLine();
							            }
							            catch (IOException e)
							            {
							                e.printStackTrace();
							            }
							            return str;
									}
									public int nextInt()
									{
										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 long nextLong() 
									{
										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 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 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 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);
									}
								}
							 	
								public static void main(String args[]) throws Exception
								{
									new Thread(null, new Main(),"Main",1<<26).start();
								}
								int MAXN = 1000001;
								ArrayList<Integer> adj[];
	
								
								int[] dx = {1,-1,0,0};
								int[] dy = {0,0,1,-1};
								Pair[] p;
								public void run() 
								{
									PrintWriter w= new PrintWriter(System.out);
						            InputReader sc = new InputReader(System.in);
						            int n = sc.nextInt();
						            int h = sc.nextInt();
						            int wi = sc.nextInt();
						            int one = n-wi+1;
						            int two = n-h+1;
						            w.println(one*two);
									w.close();
								}
								static long gcd(long a,long b) {
									
									      if (b == 0) 
									        return a; 
									      return gcd(b, a % b);  
									    
								}
								static class Pair implements Comparable<Pair>{
									long a;
									int b;
									
									Pair(long a, int b){
										this.a = a;
										this.b = b;
										
									}
									@Override
									public int compareTo(Pair o) {
										// TODO Auto-generated method stub
										if(this.a == o.a) {
											return Long.compare(o.b,this.b);
										}
										return Long.compare(o.a,this.a);
									}
									public boolean equals(Object o) {
										Pair p = (Pair)o;
										return this.a == p.a && this.b == p.b;
									}
									public int hashCode(){
										return Long.hashCode(a)*27 + Long.hashCode(b)* 31;
									}
								}
								
							}

Measured memory_bytes: 25172