#include <bits/stdc++.h>
#include <map>
#include <algorithm> 
#include <vector> 
#include <string.h> 
#include <math.h> 
#include <stdio.h> 
#include <stdlib.h> 
#include <chrono> 
#include <thread> 
#include <iomanip>
#include <typeinfo>

//define
#define trav(i,v)   for(auto i: v)
#define rep(i,n)    for(int i=0;i<n;i++)
#define repu(i,k,n) for(int i=k;i<=n;i++)
#define repd(i,k,n) for(int i=k;i>=n;i--)
#define se second
#define fi first
#define pb push_back
#define mp make_pair
#define all(v)  v.begin(), v.end()
#define itn int 

//typedef
typedef long long int ll;
typedef unsigned long long int ull;
typedef long double ld;
typedef std::pair<int, int> pii;
typedef std::vector<int> vi;
typedef std::vector< pii > vii;
typedef std::vector< ll > vll;
typedef std::vector< std::pair < pii, int > > vpp;
 
// const long long MOD = 1000000007;
const long long MOD = 998244353;
const long long inf = 1000000000000000000;

using namespace std;

ll modpow(ll x,ll n){
    ll res=1;
    while(n>0){
        if(n&1) res=res*x%MOD;
        x=x*x%MOD;
        n>>=1;
    }
    return res;
}

ll power(ll x, ll n)
{
    ll res=1;
    while(n>0){
        if(n&1) res=res*x;
        x=x*x;
        n>>=1;
    }
    return res;
}

void solve()
{
    ll a, b, c;
    cin>>a>>b>>c;
    ll x=1;
    x*=a;
    x%=MOD;
    x*=(a+1);
    x%=MOD;
    x*=modpow(2,MOD-2);
    x%=MOD;
    a=b;
    x*=a;
    x%=MOD;
    x*=(a+1);
    x%=MOD;
    x*=modpow(2,MOD-2);
    x%=MOD;
    a=c;
    x*=a;
    x%=MOD;
    x*=(a+1);
    x%=MOD;
    x*=modpow(2,MOD-2);
    x%=MOD;
    cout<<x<<endl;
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    int t = 1, tt=1;
    // cin>>t;    
    while(tt<=t)
    {
        // cout<<"Case #"<<tt<<": ";
        solve();
        tt++;
    }
    cerr << "Time : " << 1000 * ((double)clock()) / (double)CLOCKS_PER_SEC << "ms\n";
}
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define endl '\n'
#define all(x) (x).begin(),(x).end()
const int INF=1000000000+5;
const int N=300+5;
const ll oo=1e18+5;
const ll mod=998244353;

ll inv2;

ll mul(ll a, ll b){
	return a*b%mod;
}

ll poww(ll a,ll b){
	ll r=1;
	while(b){
		if(b&1) r=mul(r,a);
		a=mul(a,a);
		b>>=1;
	}
	return r;
}

ll sum(ll x){
	return mul(x,mul(x+1,inv2));
}

int main(){
	ios::sync_with_stdio(0); cin.tie(0);
	ll a,b,c;
	cin>>a>>b>>c;
	inv2=poww(2ll,mod-2);
	cout<<mul(sum(a),mul(sum(b),sum(c)));
	return 0;	
}
