#pragma GCC optimize("O3,Ofast,unroll-loops")

#include<bits/stdc++.h>
#define rep(i,s,n) for (int i = (int)(s); i < (int)(n); i++)
#define all(v) begin(v),end(v)
using namespace std;
using ll = long long;
using vl=vector<ll>;
using vs=vector<string>;
bool chmin(auto &a, auto b){ return a > b ? a = b, 1 : 0; }
bool chmax(auto &a, auto b){ return a < b ? a = b, 1 : 0; }

bool check(vl a,vl b){
    for(auto &x:a) x=abs(x);
    for(auto &x:b) x=abs(x);
    sort(all(a));
    sort(all(b));
    return a==b&&0<a[0]&&a[0]<a[1]&&a[1]<a[2];
}

ll f(ll A,ll B,ll C){
    ll rs=0;
    rep(x,-A,A+1)rep(y,-B,B+1)rep(z,-C,C+1){
        vl b=vl{x,y,z};
        sort(all(b));
        do{
            rep(S,0,8){
                vl c=b;
                rep(k,0,3)if(S&1<<k) c[k]*=-1;
                ll u=c[0],v=c[1],w=c[2];
                vl a;
                a.emplace_back(abs(x-u));
                a.emplace_back(abs(y-v));
                a.emplace_back(abs(z-w));
                if(abs(u)<=A&&abs(v)<=B&&abs(w)<=C&&check(a,b)) rs++;
            }
        }while(next_permutation(all(b)));
    }
    return rs>>1;
}

ll g(ll A,ll B,ll C){
    ll rs=0;
    rep(i,0,3){
        rep(y,1,A+1)rep(x,1,y){
            if(x+y<=min(B,C)){
                rs++;
//                cout<<x<<' '<<y<<' '<<A<<' '<<min(B,C)<<endl;
            }
        }
        swap(A,B);
        swap(B,C);
    }
    return rs<<4;
}

ll calc_sum(ll n,ll d){
    return (n+d)/d*(n+n%d)/2;
}

ll calc(ll A,ll B){
    if(A<0||B<0) return 0;
    ll rs;
    if(B>=2*A) rs=calc_sum(A+1,1);
    else if(B>=A) rs=calc_sum(2*A-B+1,2)+(3*A-B+3)*(B-A)/2;
    else rs=calc_sum(B+1,2);
//    cout<<A<<' '<<B<<' '<<rs<<endl;
    return rs;
}

ll h(ll A,ll B,ll C){
    ll rs=0;
    rep(i,0,3){
        rs+=calc(A-2,min(B,C)-3);
        swap(A,B);
        swap(B,C);
    }
    return rs<<4;
}

int main(){
    cin.tie(0)->sync_with_stdio(0);

    ll A,B,C;
    cin>>A>>B>>C;
    cout<<h(A,B,C)<<endl;

    // g(4,6,6);
    // h(4,6,6);

    // ll n;
    // cin>>n;
    // rep(A,1,n)rep(B,A,n)rep(C,B,n){
    //     cout<<A<<' '<<B<<' '<<C<<endl;
    //     ll u=h(A,B,C);
    //     ll v=g(A,B,C);
    //     if(u!=v) cout<<u<<' '<<v<<endl;
    //     assert(u==v);
    // }

    // cout<<g(3,3,3)<<endl;
    // cout<<g(3,3,2)<<endl;
    // cout<<g(3,2,2)<<endl;

    // return 0;

    // ll n;
    // cin>>n;
    // rep(x,0,n+1)rep(y,x,n+1)rep(z,y,n+1){
    //     vl b=vl{x,y,z};
    //     do{
    //         rep(S,0,8){
    //             vl c=b;
    //             rep(k,0,3)if(S&1<<k) c[k]*=-1;
    //             vl a;
    //             a.emplace_back(abs(x-c[0]));
    //             a.emplace_back(abs(y-c[1]));
    //             a.emplace_back(abs(z-c[2]));
    //             sort(all(a));
    //             if(a==vl{x,y,z}){
    //                 cout<<x<<' '<<y<<' '<<z<<' '<<c[0]<<' '<<c[1]<<' '<<c[2]<<endl;
    //                 assert(x+y==z);
    //             }
    //         }
    //     }while(next_permutation(all(b)));
    // }
}