#include <iostream>
#include <fstream>
#define MOD 1999999973
using namespace std;
ifstream f("cladire.in");
ofstream g("cladire.out");
const int N = 1001;
const int M = 9901;
inline int suma(int x,int y){ return x+y<MOD?x+y:x+y-MOD;}
int n,m,a[N][N];
int main()
{
    f>>n>>m;
    for(int i=1;i<=n;i++)
        a[i][1]=1;
    for(int j=1;j<=m;j++)
        a[1][j]=1;
    for(int i=2;i<=n;i++)
        for(int j=1;j<=m;j++)
            a[i][j]=suma(a[i-1][j],a[i][j+1]);
    g<<a[n][m];
    return 0;
}