// 有效代码 2 行,典型的初中数学排列组合问题: (m + n)!/m!/n!
const exec = (line:string)=>{
    const [m,n] = line.split(" ").map(x=>parseInt(x,10));
    return X(m+n)/X(m)/X(n);
};
const X = (x)=>new Array(x).fill(null).map((_,i)=>i+1).reduce((a,b)=>a*b);

// ACM 八股代码真的烦
const readline = require('readline');
const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});
rl.on('line', (line:string) => outputs.push(`${exec(line)}`));
rl.on("close",()=>outputs.forEach(res=>console.log(res)));
const outputs: string[] = [];