#include <bits/stdc++.h> using namespace std; long long end_x,end_y,position[30][30]; int main(){ cin>>end_x>>end_y; position[0][1]=1; for(int i=1;i<=end_x+1;i++){ for(int j=1;j<=end_y+1;j++){ if(position[i][j]==-1){ position[i][j]=0; }else{ position[i][j]=position[i-1][j]+position[i][j-1]; } } } cout<<position[end_x+1][end_y+1]; return 0; }