2019 Multi-University Training Contest 2

 1 #include <bits/stdc++.h>
 2 
 3 using namespace std;
 4 typedef long long ll;
 5 const ll mod=1e6+3;
 6 ll ans[mod+1],n;
 7 int main(){
 8     ans[0]=1;
 9     for (int i=1;i<=mod;i++){
10         ans[i]=ans[i-1]*i%mod;
11     }
12     while (~scanf("%lld",&n)){
13         if (n>=mod){
14             printf("0\n");
15         }else{
16             printf("%lld\n",ans[n]);
17         }
18     }
19 }