1 #include <bits/stdc++.h>
 2 using namespace std;
 3 typedef long long ll;
 4 const ll mod = 998244353;
 5 const int maxn = 5003;
 6 ll C[maxn][maxn],jie[maxn];
 7 void init(){
 8     C[0][0]=C[1][0]=C[1][1]=1;
 9     for(int i=2;i<maxn;i++){
10         C[i][0]=C[i][i]=1;
11         for(int j=1;j<i;j++)
12             C[i][j]=(C[i-1][j-1]+C[i-1][j])%mod;
13     }
14     jie[0]=1;
15     for(ll i=1;i<maxn;i++)    jie[i]=jie[i-1]*i%mod;
16 }
17 int main(){
18     init();
19     ll a,b,c;
20     scanf("%lld%lld%lld",&a,&b,&c);
21     ll ans1=0,ans2=0,ans3=0;
22     ll t;
23     t=min(a,b);
24     for(ll i=0;i<=t;i++)    ans1=(ans1+C[a][i]*C[b][i]%mod*jie[i]%mod)%mod;
25     t=min(b,c);
26     for(ll i=0;i<=t;i++)    ans2=(ans2+C[b][i]*C[c][i]%mod*jie[i]%mod)%mod;
27     t=min(a,c);
28     for(ll i=0;i<=t;i++)    ans3=(ans3+C[a][i]*C[c][i]%mod*jie[i]%mod)%mod;
29 
30     printf("%lld\n",(ans1*ans2%mod)*ans3%mod);
31 }