package main

import (
    "fmt"
)

func loop(n,m int)int{
    if n==0 || m == 0{
        return 1
    }
    return loop(n-1, m) + loop(n, m-1)
}

func main() {
var n,m int
fmt.Scan(&n,&m)
count := loop(n, m)
fmt.Print(count)
}