#include<bits/stdc++.h>
#include<cstdio>
#define ll long long
#define fi first
#define se second
using namespace std;
typedef pair<ll,ll> lp;
typedef vector<vector<ll>> vvl;
const int inf=0x3f3f3f3f;
const ll mod=1e9+7;
ll dp[10005][100];//s题
vector<int> a;//s题
int d;   //s题
void A() {
    int n;
    cin>>n;
    vector<int> a(n,0);
    for(int i=0; i<n; i++)
        cin>>a[i];
    vector<int> dp(n+1,inf);
    dp[0]=0;
    for(int i=1; i<n; i++) {
        dp[i]=min(dp[i],dp[i-1]+abs(a[i]-a[i-1]));
        if(i>=2)
            dp[i]=min(dp[i],dp[i-2]+abs(a[i]-a[i-2]));
    }
    cout<<dp[n-1]<<endl;

}
void B() {
    int n,k;
    cin>>n>>k;
    vector<int> dp(n+1,inf);
    vector<int> h(n,0);
    for(int i=0; i<n; i++)
        cin>>h[i];
    dp[0]=0;
    for(int i=1; i<n; i++) {
        for(int len=1; len<=min(k+1,i+1); len++) {
            int j=i-len+1;
            dp[i]=min(dp[i],dp[j]+abs(h[j]-h[i]));
        }
    }
    cout<<dp[n-1]<<endl;
}
void C() {
    int n;
    cin>>n;
    vector<vector<int>> a(n,vector<int>(3,0));
    for(int i=0; i<n; i++)
        cin>>a[i][0]>>a[i][1]>>a[i][2];
    vector<vector<int>> dp(n,vector<int>(3,0));
    dp[0][0]=a[0][0];
    dp[0][1]=a[0][1];
    dp[0][2]=a[0][2];
    for(int i=1; i<n; i++) {
        for(int j=0; j<3; j++) {
            for(int k=0; k<3; k++) {
                if(j==k)
                    continue;
                dp[i][j]=max(dp[i][j],dp[i-1][k]+a[i][j]);
                //cout<<dp[i][j]<<endl;
            }
        }
    }
    cout<<max(dp[n-1][0],max(dp[n-1][1],dp[n-1][2]))<<endl;
}
void D() {
    ll n,W;
    cin>>n>>W;
    vector<lp> p;
    for(int i=0; i<n; i++) {
        ll a,b;
        cin>>a>>b;
        p.emplace_back(a,b);
    }
    sort(p.begin(),p.end());
    vector<ll> dp(W+1,0);
    for(int i=0; i<n; i++) {
        for(int j=W; j>=p[i].first; j--) {
            if(j>0)
                dp[j]=max(dp[j],dp[j-1]);
            dp[j]=max(dp[j],dp[j-p[i].fi]+p[i].se);
        }
    }
    cout<<dp[W]<<endl;

}
void E() {
    //价值比较小，将dp[i]转化为获得当前i的价值的最小体积，然后根据W寻找符合要求的解；
    int n,W;
    cin>>n>>W;
    vector<ll> w(n,0);
    vector<ll> v(n,0);
    for(int i=0; i<n; i++)
        cin>>w[i]>>v[i];
    vector<ll> dp(100005,inf);
    dp[0]=0;
    int res=0;
    for(int i=0; i<n; i++) {
        for(int j=1e5; j>=v[i]; j--) {
            dp[j]=min(dp[j],dp[j-v[i]]+w[i]);
            if(dp[j]<=W) {
                res=max(res,j);
            }
        }
    }
    cout<<res<<endl;

}
void F() {
    string s,t;
    cin>>s>>t;
    int n=s.size(),m=t.size();
    vector<vector<int>> dp(n+1,vector<int>(m+1,0));
    for(int i=1; i<=n; i++) {
        for(int j=1; j<=m; j++) {
            char a=s[i-1],b=t[j-1];
            if(a==b) {
                dp[i][j]=max(dp[i][j],dp[i-1][j-1]+1);
            }
            dp[i][j]=max(dp[i][j],max(dp[i-1][j],dp[i][j-1]));
        }
    }
    int i=n,j=m;
    stack<char> st;
    while(i!=0&&j!=0) {
        char a=s[i-1],b=t[j-1];
        if(a==b) {
            st.push(a);
            j--;
            i--;
        } else {
            if(dp[i][j]==dp[i-1][j])
                i--;
            else
                j--;
        }
    }
    string res;
    while(!st.empty()) {
        res+=st.top();
        st.pop();
    }
    cout<<res<<endl;
}
int Ghelper(vector<int>& dp,vector<vector<int>>& edge,int cur,int& ans) {
    if(dp[cur]!=-1)
        return dp[cur];
    int res=0;
    for(auto nb:edge[cur]) {
        res=max(res,Ghelper(dp,edge,nb,ans)+1);
    }
    ans=max(ans,res);
    dp[cur]=res;
    return res;
}
void G() {
    int n,m;
    cin>>n>>m;
    vector<vector<int>> edge(n+1,vector<int>());
    for(int i=0; i<m; i++) {
        int x,y;
        cin>>x>>y;
        edge[x].push_back(y);
    }
    vector<int> dp(n+1,-1);
//    vector<bool> vis(n+1,0);
    int res=0;
    for(int i=1; i<=n; i++) {
//        if(vis[i]) continue;
//        vis[i]=true;
        Ghelper(dp,edge,i,res);
    }
    cout<<res<<endl;
}
void H() {
    int H,W;
    cin>>H>>W;
    vector<vector<char>> grid(H+1,vector<char>(W+1,'.'));
    vector<vector<ll>> dp(H+1,vector<ll>(W+1,0));
    for(int i=1; i<=H; i++) {
        for(int j=1; j<=W; j++) {
            cin>>grid[i][j];
        }
    }
    dp[1][1]=1;
    for(int i=1; i<=H; i++) {
        for(int j=1; j<=W; j++) {
            if(i==1&&j==1)
                continue;
            if(grid[i][j]=='#')
                dp[i][j]=0;
            else {
                dp[i][j]=(dp[i-1][j]+dp[i][j-1])%mod;
            }
        }
    }
    cout<<dp[H][W]<<endl;
}
void I() {
    int n;
    cin>>n;
    vector<vector<double>> dp(n+1,vector<double>(n+1,0.0));
    vector<double> p(n,0.0);
    for(int i=0; i<n; i++)
        cin>>p[i];
    dp[0][0]=1.0;
    for(int i=1; i<=n; i++) {
        for(int j=0; j<=i; j++) {
            if(j>0)
                dp[i][j]+=dp[i-1][j-1]*p[i-1];
            dp[i][j]+=dp[i-1][j]*(1-p[i-1]);
        }
    }
    double res=0.0;
    for(int i=(n+1)/2; i<=n; i++)
        res+=dp[n][i];
    printf("%.10f\n",res);
}
double JHelper(vector<vector<vector<double>>>& dp,int a,int b,int c,int n) {
    //cout<<a<<" "<<b<<" "<<c<<endl;
    if(a==0&&b==0&&c==0)
        return 0;
    if(dp[a][b][c]>0)
        return dp[a][b][c];
    double sum=a+b+c;
    double ans=1.0*n/sum;
    if(a)
        ans+=JHelper(dp,a-1,b,c,n)*(1.0*a/sum);
    if(b)
        ans+=JHelper(dp,a+1,b-1,c,n)*(1.0*b/sum);
    if(c)
        ans+=JHelper(dp,a,b+1,c-1,n)*(1.0*c/sum);
    dp[a][b][c]=ans;
    return ans;
}
void J() {
    int n;
    cin>>n;
    vector<int> a(n,0);
    for(int i=0; i<n; i++)
        cin>>a[i];
    int cnt[4]= {0,0,0,0};
    for(int i:a) {
        cnt[i]++;
    }
    //cout<<"OK"<<endl;
    vector<vector<vector<double>>> dp(n+1,vector<vector<double>>(n+1,vector<double>(n+1,-1.0)));
    printf("%.13f\n",JHelper(dp,cnt[1],cnt[2],cnt[3],n));
}
//int KHelper(vector<int>& a,vector<int>& dp,int cur,int n)
//{
//    cout<<cur<<" "<<endl;
//    if(dp[cur]!=-1) return dp[cur];
//    dp[cur]=0;
//    for(int i=0;i<n&&cur>=a[i];i++){
//        dp[cur]|=1-KHelper(a,dp,cur-a[i],n);
//        if(dp[cur]==1) break;
//    }
//    return dp[cur];
//}
void K() {
    int n,k;
    cin>>n>>k;
    vector<int> a(n+1,0);
    vector<int> dp(k+3,-1);
    for(int i=0; i<n; i++) {
        cin>>a[i];
    }
//    if(KHelper(a,dp,k,n)==1) cout<<"First"<<endl;
//    else cout<<"Second"<<endl;
    dp[0]=0;
    for(int i=1; i<=k; i++) {
        dp[i]=0;
        for(int j=0; j<n&&a[j]<=i; j++) {
            dp[i]|=1-dp[i-a[j]];
            if(dp[i]==1)
                break;
        }
    }
    if(dp[k]==1)
        cout<<"First"<<endl;
    else
        cout<<"Second"<<endl;
}
void L() {
    int n;
    cin>>n;
    vector<ll> a(n+1,0);
    for(int i=1; i<=n; i++)
        cin>>a[i];
    vector<vector<ll>> dp(n+2,vector<ll>(n+2,0));
    for(int len=1; len<=n; len++) {
        for(int i=1; i+len<=n+1; i++) {
            int j=i+len-1;
            if((n-len)%2==0) {
                dp[i][j]=max(dp[i+1][j]+a[i],dp[i][j-1]+a[j]);
            } else {
                dp[i][j]=min(dp[i+1][j]-a[i],dp[i][j-1]-a[j]);
            }
        }
    }
    cout<<dp[1][n]<<endl;
}
void M() {
    int n,K;
    cin>>n>>K;
    vector<int> a(n+1,0);
    for(int i=1; i<=n; i++)
        cin>>a[i];
    vector<vector<int>> dp(n+1,vector<int>(K+1,0));
    for(int i=0; i<=n; i++)
        dp[i][0]=1;
//    for(int i=0;i<=K;i++) dp[0][i]=1;
    for(int i=1; i<=n; i++) {
        dp[i][0]=1;
        for(int j=0; j<K; j++) {
            dp[i][j+1]=(dp[i][j+1]+dp[i][j]+dp[i-1][j+1])%mod;
            if(j>=a[i]) {
                dp[i][j+1]=(dp[i][j+1]-dp[i-1][j-a[i]]+mod)%mod;
            }

        }
    }
    cout<<dp[n][K]<<endl;
}
void N() {
    int n;
    cin>>n;
    vector<ll> a(n+1,0);
    vector<ll> sum(n+1,0);
    vector<vector<ll>> dp(n+1,vector<ll>(n+1,-1));
    for(int i=1; i<=n; i++) {
        cin>>a[i];
        sum[i]=sum[i-1]+a[i];
    }
    for(int i=1; i<=n-1; i++) {
        dp[i][i]=0;
        dp[i][i+1]=a[i]+a[i+1];
    }
    dp[n][n]=0;
    for(int len=3; len<=n; len++) {
        for(int i=1; i+len-1<=n; i++) {
            int j=i+len-1;
            for(int k=i; k<j; k++) {
                if(dp[i][j]==-1)
                    dp[i][j]=dp[i][k]+dp[k+1][j]+sum[j]-sum[i-1];
                else
                    dp[i][j]=min(dp[i][j],dp[i][k]+dp[k+1][j]+sum[j]-sum[i-1]);
            }
        }
    }
    cout<<dp[1][n]<<endl;
}
void O() {
    int n;
    cin>>n;
    vector<vector<int>> cnt(n+1,vector<int>(n+1,0));
    for(int i=1; i<=n; i++) {
        for(int j=1; j<=n; j++) {
            cin>>cnt[i][j];
        }
    }
    vector<int> dp((1<<n),0);
    dp[0]=1;
    for(int mask=1; mask<(1<<n); mask++) {
        bitset<32> bt(mask);
        int i=bt.count();
        //cout<<i<<endl;
        for(int j=0; j<n; j++) {
            if(cnt[i][j+1]==1&&((mask&(1<<j))!=0)) {
                dp[mask]=(dp[mask]+dp[mask-(1<<j)])%mod;
            }
        }
    }
    cout<<dp[(1<<n)-1]<<endl;
}
ll PHelper(vector<vector<ll>>& dp,vector<vector<int>>& child,int cur,int flag) {
    if(dp[cur][flag]!=-1)
        return dp[cur][flag];
    ll ans=1;
    for(auto c:child[cur]) {
        if(flag==1)
            ans=(ans*PHelper(dp,child,c,0))%mod;
        else
            ans=(ans*(PHelper(dp,child,c,0)+PHelper(dp,child,c,1)))%mod;
    }
    dp[cur][flag]=ans;
    return ans;
}
void P() {
    int n;
    cin>>n;
    vector<vector<int>> child(n+1,vector<int>());
    vector<vector<ll>> dp(n+1,vector<ll>(2,-1));
    vector<vector<int>> edge(n+1,vector<int>());
    for(int i=0; i<n-1; i++) {
        int x,y;
        cin>>x>>y;
        edge[x].push_back(y);
        edge[y].push_back(x);
    }
    vector<bool> vis(n+1,0);
    vis[1]=true;
    queue<int> q;
    q.push(1);
    while(!q.empty()) {
        auto u=q.front();
        q.pop();
        for(auto e:edge[u]) {
            if(vis[e])
                continue;
            vis[e]=true;
            child[u].push_back(e);
            q.push(e);
        }
    }
    ll res=(PHelper(dp,child,1,0)+PHelper(dp,child,1,1))%mod;
    cout<<res<<endl;
}
void Q() {
    set<lp> cnt;
    int n;
    cin>>n;
    vector<ll> h(n+1,0);
    vector<ll> a(n+1,0);
    for(int i=0; i<n; i++)
        cin>>h[i];
    for(int i=0; i<n; i++)
        cin>>a[i];
    ll res=0;
    cnt.insert({0,0});
    for(int i=0; i<n; i++) {
        //
        ll cur=0;
        auto it=prev(cnt.lower_bound({h[i],0}));
        cur=it->second+a[i];
        while(true) {
            auto next=cnt.lower_bound({h[i],0});
            if(next!=cnt.end()&&next->second<=cur) {
                cnt.erase(next);
            } else
                break;
        }
        res=max(res,cur);
        cnt.insert({h[i],cur});
    }
    cout<<res<<endl;
}
void R() {
    ll N,K;
    cin>>N>>K;
    vector<vector<ll>> a(N+1,vector<ll>(N+1,0));
    for(int i=1; i<=N; i++) {
        for(int j=1; j<=N; j++) {
            cin>>a[i][j];
        }
    }
    auto amul=[](vvl aa,vvl bb,int n) {
        vector<vector<ll>> t(n+1,vector<ll>(n+1,0));
        for(int i=1; i<=n; i++) {
            for(int k=1; k<=n; k++) {
                for(int j=1; j<=n; j++) {
                    t[i][j]=(t[i][j]+aa[i][k]*bb[k][j])%mod;
                }
            }
        }
        return t;
    };
    auto power=[&amul](ll k,vvl cur,int n) {
        vvl res(n+1,vector<ll> (n+1,0));
        for(int i=1; i<=n; i++)
            res[i][i]=1;
        while(k>0) {
            if(k&1)
                res=amul(res,cur,n);
            k=k>>1;
            cur=amul(cur,cur,n);
        }
        return res;
    };
    ll ans=0;
    vvl f=power(K,a,N);
    for(int i=1; i<=N; i++) {
        for(int j=1; j<=N; j++) {
            ans+=f[i][j];
            ans%=mod;
        }
    }
    cout<<ans<<endl;
}
ll SHelper(int pos,int state,bool limit) {
    //cout<<pos<<" "<<pre<<" "<<state<<" "<<limit<<endl;
    if(pos==-1)
        return state==0?1ll*1:1ll*0;
    if(!limit&&dp[pos][state]!=-1)
        return dp[pos][state];

    int up=limit?a[pos]:9;
    //cout<<"ok"<<endl;
    ll ans=0;
    for(int i=0; i<=up; i++) {
        ans=(ans+SHelper(pos-1,(state+i)%d,limit&&(i==a[pos])))%mod;
    }

    if(!limit)
        dp[pos][state]=ans;
    return ans;
};
void S() {
    string k;
    cin>>k>>d;
    int n=k.size()+1;
    auto solve=[](string s)->ll{
        a.clear();
        memset(dp,-1,sizeof(dp));
        for(int i=s.size()-1; i>=0; i--)
            a.push_back(s[i]-'0');
        return SHelper(s.size()-1,0,true);
    };
    cout<<(mod+solve(k)-solve("0"))%mod<<endl;
}
void T() {
    int n;
    cin>>n;
    string s;
    cin>>s;
    vector<vector<ll>> dpt(n+2,vector<ll> (n+2,0));
    dpt[1][1]=1;
    for(int l=2; l<=n; l++) {
        if(s[l-2]=='<') {
            for(int x=1; x<=l; x++) {
                dpt[l][x]=(dpt[l-1][x-1]+dpt[l][x-1])%mod;
                //if(dp[l][x]<0) dp[l][x]=(dp[l][x]+mod)%mod;
            }
        } else {
            for(int x=l; x>=1; x--) {
                dpt[l][x]=(dpt[l][x+1]+dpt[l-1][x])%mod;
                //if(dp[l][x]<0) dp[l][x]=(dp[l][x]+mod)%mod;
            }
        }

    }
    ll ans=0;
    for(int i=1; i<=n; i++) {
        ans=(ans+dpt[n][i])%mod;
    }
    cout<<ans%mod<<endl;
}
void U() {
    int n;
    cin>>n;
    vector<vector<ll>> a(n+1,vector<ll>(n+1));
    for(int i=0;i<n;i++){
        for(int j=0;j<n;j++){
            cin>>a[i][j];
        }
    }
    int maxn=(1<<n);
    vector<ll> cost(maxn,0);
    vector<ll> dp(maxn,0);
    for(int mask=0;mask<maxn;mask++){
        for(int i=0;i<n;i++){
            for(int j=i+1;j<n;j++){
                if(((1<<i)&mask) && ((1<<j)&mask)){
                    cost[mask]+=a[i][j];
                }
            }
        }
    }
    for(int mask=0;mask<maxn;mask++){
        for(int submask=mask;submask>0;submask=(submask-1)&mask){
            dp[mask]=max(dp[mask],dp[mask-submask]+cost[submask]);
        }
    }
    cout<<dp[maxn-1]<<endl;
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    U();
}


Measured memory_bytes: 4300