Language: C

#include <iostream>
#include <cstdio>
#include <cstring>
#include <string>
#include <cmath>
#include <ctype.h>
#include <limits.h>
#include <cstdlib>
#include <algorithm>
#include <vector>
#include <queue>
#include <map>
#include <stack>
#include <set>
#include <bitset>
#define CLR(a) memset(a, 0, sizeof(a))
#define REP(i, a, b) for(ll i = a;i < b;i++)
#define REP_D(i, a, b) for(ll i = a;i <= b;i++)

typedef long long ll;

using namespace std;

const ll maxn = 1000 + 10;
const ll MOD = 1000003;
ll dp[maxn], dp_a[maxn][maxn], dp_b[maxn][maxn];
ll sum_a[maxn][maxn], sum_b[maxn][maxn];
ll n, k;

ll pow_mod(ll x, ll n)
{
    if(n==0)
    {
        ll t = 1;
        return t;
    }
    x %= MOD;
    ll xx = (x*x)%MOD;
    ll nn = n/2;
    ll res = pow_mod(xx, nn);
    if(n%2==1)
    {
        res = (res*x)%MOD;
    }
    return res;
}
ll gcd(ll x, ll y)
{
    if(y==0)
    {
        return x;
    }
    return gcd(y, x%y);
}

void getDp()
{
    CLR(dp_a);
    CLR(dp_b);
    CLR(sum_a);
    CLR(sum_b);

    dp_a[1][1] = 1;
    sum_a[1][1] = 1;

    for(ll i = 2; i <= n; i++)
    {
        if(i<=k)
        {
            dp_a[i][i] = 1;
        }
        ll key = min(i-2, k);
        for(ll j = 1; j<=key; j++)
        {
            ll limit = i - k - 1;
            limit = max(0LL, limit);

            dp_a[i][j] = ((sum_b[i-1][j] - sum_b[limit][j])%MOD + MOD)%MOD;

            //dp_b[i][j] = ((sum_a[i-1][j] - sum_a[limit][j])%MOD + MOD)%MOD;
            //printf("i is %lld j is %lld dp_b is %lld\n", i, j, dp_b[i][j]);
        }
        key = min(i-1, k);
        for(ll j = 1; j<=key; j++)
        {
            ll limit = i - k - 1;
            limit = max(0LL, limit);
            dp_b[i][j] = ((sum_a[i-1][j] - sum_a[limit][j])%MOD + MOD)%MOD;
            //printf("i is %lld j is %lld dp_b is %lld\n", i, j, dp_b[i][j]);
        }
        for(ll j = 1; j<=i; j++)
        {
            sum_a[i][j] = (sum_a[i-1][j] + dp_a[i][j])%MOD;
            sum_b[i][j] = (sum_b[i-1][j] + dp_b[i][j])%MOD;
        }
    }
    CLR(sum_b);
    for(ll i = 2;i <= n;i++)
    {
        //sum_b[i][0] = 0;
        for(ll j = 1;j <= n;j++)
        {
            sum_b[i][j] = (sum_b[i][j-1]+dp_b[i][j])%MOD;
        }
    }
    CLR(dp);
    for(ll i = 1; i <= n; i++)
    {
        for(ll j= 1;j<=min(k, i-1);j++)
            dp[i] = (dp[i]+dp_b[i][j])%MOD;
//        if(i<=k)
//        {
//            dp[i] = (dp[i]+1)%MOD;
//        }
        for(ll j = 1; j <= min(k,i - 2); j++)
        {
                ll lft = k-j;
                dp[i] = (dp[i]+sum_b[i-j][k-j])%MOD;
        }
//        if(i <= k)
//        {
//            dp[i] = (dp[i]+1)%MOD;
//        }
        //printf(" i is %lld   %lld\n", i, dp[i]);
        dp[i] = (2*dp[i])%MOD;

    }
}

void solve()
{
    getDp();
    ll ans = dp[n];
    for(ll i = 1;i<n;i++)
    {
        ll t = gcd(i, n);
        ans = (ans + dp[t])%MOD;
    }
    ans = (ans*pow_mod(n, MOD-2))%MOD;
    if(n <= k)
    {
        ans = (ans + 2)%MOD;
    }
    printf("%lld\n", ans);
}

int main()
{
  //  freopen("8Hin.txt", "r", stdin);
    //freopen("8Hout.txt", "w", stdout);
    while(scanf("%lld%lld", &n, &k) != EOF)
    {
        if(!n && !k)
            break;
        solve();
    }
    return 0;
}

Compiler output:
main.c:1:10: fatal error: iostream: No such file or directory
    1 | #include <iostream>
      |          ^~~~~~~~~~
compilation terminated.