#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define sp <<" "<<
bool isprime(ll n){
    if (n <= 1)return false;ll g=sqrt(n);
    for (ll i = 2; i <= g; i++)if (n % i == 0)return false;
    return true;
}
ll MOD=998244353;
ll power(ll base, ll exp)
{
    if(exp==1)return base;
    else{if(exp%2==0){ll base1=(pow(power(base, exp/2),2));return base1%MOD;}
        else{ll ans=(base*pow(power(base,(exp-1)/2),2));return ans%MOD;}}
}
ll temp,temp1,temp2;
int main()
{
    /*#ifndef ONLINE_JUDGE
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout);
    #endif*/
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);

    ll a[3];
    ll res=1;
    cin>>a[0]>>a[1]>>a[2];

    for(int i=0;i<3;i++)
    {
        //cout<<res<<endl;
        if(a[i]%2)
        {
            res*=(a[i]+1)/2;
            res%=MOD;
            res*=a[i];
            res%=MOD;
        }
        else
        {
            res*=(a[i])/2;
            res%=MOD;
            res*=a[i]+1;
            res%=MOD;
        }
    }
    cout<<res;
    return 0;
}

#include <bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
#define ll long long int
#define ff first
#define ss second
typedef tree<pair<ll,ll>,null_type,less<pair<ll,ll>>,rb_tree_tag,
              tree_order_statistics_node_update>pbds;
//order_of_key:index number if it was there in sorted array
//find_by_order:value at 3rd index in sorted array.
const ll maxs=1e6+5;
ll root[maxs];

class cmp{
  bool operator()(const ll &a,const ll &b)
  {
      return a<b;
  }
};
void init()
{
    iota(root,root+maxs,0);
}
ll find(ll u)
{
    ll f;
    if(root[u]==u)
    return u;
    else
    {
        ll f=find(root[u]);
        root[u]=f;
        return f;
    }
}
void Union(ll x,ll y)
{
    ll u=find(x);
    ll v=find(y);
    root[v]=u;
}
ll power(ll x,ll y,ll p)
{
    ll res=1;
    x=x%p;
    while(y>0)
    {
        if(y&1)
        res=(res*x)%p;
        
        y=y>>1;
        x=(x*x)%p;
    }
    return res;
}

int main()
{
    ll t,n,i,k,y,x,j;
   ll a,b,c,d;
   cin>>a>>b>>c>>d;
   cout<<a*d-b*c;
    return 0;
    
}
