import java.util.Scanner;
public class DP {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
while(scanner.hasNext()){
int n = scanner.nextInt();
int m = scanner.nextInt();
//排列组合法
int top = factorial(n+m);
int behind = factorial(n)*factorial(m);
int count =top/behind;
System.out.println(count);
//动态规划法
/* int [][] dp = new int [n+1][m+1];
for(int i=0;i<=m;i++){
dp[0][i]=1;
}
for(int j =0;j<=n;j++){
dp[j][0]=1;
}
for(int i=1;i<=n;i++){
for(int j=1;j<=m;j++){
dp[i][j]=dp[i-1][j]+dp[i][j-1];
}
}
System.out.println(dp[n][m]);*/
}
}
public static int factorial(int n){
int sum = 1;
for(int i =1;i<=n;i++){
sum*=i;
}
return sum;
}
}
