#include <functional>
#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdlib>
#include <cassert>
#include <sstream>
#include <numeric>
#include <string>
#include <vector>
#include <cstdio>
#include <bitset>
#include <cmath>
#include <ctime>
#include <queue>
#include <stack>
#include <map>
#include <set>

using namespace std;

#define pb push_back
#define ll long long
#define mp make_pair
#define f first
#define s second
#define pii pair < int, int >
#define pll pair < ll, ll >
#define all(s) s.begin(), s.end()
#define sz(s) (int) s.size()
#define forit(it, s) for(__typeof(s.begin()) it = s.begin(); it != s.end(); it++)
#define vi vector < int >

const int inf = (int)1e9;
int mod = 998244353;
int fact[5050];
int invfact[5050];

int binpow(int a, int b){
    int res = 1;
    while(b){
        if (b&1)
            res = res*1ll*a%mod;
        a = a*1ll*a%mod;
        b /= 2;
    }
    return res;
}

void precalc(){
    fact[0] = 1;
    for (int i=1;i<5050;i++) fact[i] = fact[i-1] *1ll* i % mod;

    for (int i=0;i<5050;i++) {
        invfact[i] = binpow(fact[i], mod-2);
    }
}

int cnk(int n, int k){
    if (k > n) return 0;
    return fact[n] * 1ll* invfact[k]%mod * invfact[n-k]%mod;
}

int calc(int a, int b){
    int res = 0;
    for (int i=0;i<=a;i++){
        res += cnk(a, i) * 1ll * cnk(b, i) % mod * fact[i] %mod;
        if (res >= mod) res -= mod;
    }
    return res;
}

int main () {
    precalc();
    int a, b, c;
    scanf("%d%d%d", &a, &b, &c);

    int ans = calc(a, b) *1ll* calc(b, c) % mod * calc(c, a) % mod;
    cout <<ans<<endl;

    return 0;
}