#include<bits/stdc++.h>
#define int long long
#define x first
#define y second
#define de(x) cout<<#x<<" = "<<x<<" "
#define deg(x) cout<<#x<<" = "<<x<<endl
using namespace std;
const int N=10010,p=1e6+3;
typedef pair<int,int> PII;
int qmi(int a,int b)
{
    int res=1%p;
    while(b)
    {
        if(b&1)res=res*a%p;
        a=a*a%p;
        b>>=1;
    }
    return res;
}
signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n,m;
    cin>>n>>m;
    int res=1;
    for(int i=n+m,j=1;j<=m;i--,j++)
    {
        res=res*i%p*qmi(j,p-2)%p;
    }
    cout<<res-1<<endl;
    return 0;
}