#include <iostream>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <algorithm>
#include <queue>
#include <vector>
#include <stack>
#include <map>
#include <set>
#include <sstream>
#include <iomanip>
#include <cmath>
#include <bitset>
#include <assert.h>

using namespace std;
typedef long long ll;
typedef set<int>::iterator ssii;

#define Cmp(a, b) memcmp(a, b, sizeof(b))
#define Cpy(a, b) memcpy(a, b, sizeof(b))
#define Set(a, v) memset(a, v, sizeof(a))
#define debug(x) cout << #x << ": " << x << endl
#define _forS(i, l, r) for(set<int>::iterator i = (l); i != (r); i++)
#define _rep(i, l, r) for(int i = (l); i <= (r); i++)
#define _for(i, l, r) for(int i = (l); i < (r); i++)
#define _forDown(i, l, r) for(int i = (l); i >= r; i--)
#define debug_(ch, i) printf(#ch"[%d]: %d\n", i, ch[i])
#define debug_m(mp, p) printf(#mp"[%d]: %d\n", p->first, p->second)
#define debugS(str) cout << "dbg: " << str << endl;
#define debugArr(arr, x, y) _for(i, 0, x) { _for(j, 0, y) printf("%c", arr[i][j]); printf("\n"); }
#define _forPlus(i, l, d, r) for(int i = (l); i + d < (r); i++)
#define lowbit(i) (i & (-i))
#define MPR(a, b) make_pair(a, b)

pair<int, int> crack(int n) {
    int st = sqrt(n);
    int fac = n / st;
    while (n % st) {
        st += 1;
        fac = n / st;
    }

    return make_pair(st, fac);
}

inline ll qpow(ll a, int n) {
    ll ans = 1;
    for(; n; n >>= 1) {
        if(n & 1) ans *= 1ll * a;
        a *= a;
    }
    return ans;
}

template <class T>
inline bool chmax(T& a, T b) {
    if(a < b) {
        a = b;
        return true;
    }
    return false;
}

ll gcd(ll a, ll b) {
    return b == 0 ? a : gcd(b, a % b);
}

ll ksc(ll a, ll b, ll mod) {
    ll ans = 0;
    for(; b; b >>= 1) {
        if (b & 1) ans = (ans + a) % mod;
        a = (a * 2) % mod;
    }
    return ans;
}

ll ksm(ll a, ll b, ll mod) {
    ll ans = 1 % mod;
    a %= mod;

    for(; b; b >>= 1) {
        if (b & 1) ans = ksc(ans, a, mod);
        a = ksc(a, a, mod);
    }

    return ans;
}

template <class T>
inline bool chmin(T& a, T b) {
    if(a > b) {
        a = b;
        return true;
    }
    return false;
}

bool _check(int x) {
    //
    return true;
}

int bsearch1(int l, int r) {
    while (l < r) {
        int mid = (l + r) >> 1;
        if(_check(mid)) r = mid;
        else l = mid + 1;
    }
    return l;
}

int bsearch2(int l, int r) {
    while (l < r) {
        int mid = (l + r + 1) >> 1;
        if(_check(mid)) l = mid;
        else r = mid - 1;
    }
    return l;
}

template<class T>
bool lexSmaller(vector<T> a, vector<T> b) {
    int n = a.size(), m = b.size();
    int i;
    for(i = 0; i < n && i < m; i++) {
        if (a[i] < b[i]) return true;
        else if (b[i] < a[i]) return false;
    }
    return (i == n && i < m);
}

// ============================================================== //

const ll inf = 1ll<<60;
const int maxn = 20 + 10;
ll S[maxn][maxn][maxn];
int a, b, c;

inline void expand(int i, int &b0, int &b1, int &b2) {
    b0 = i&1; i >>= 1;
    b1 = i&1; i >>= 1;
    b2 = i&1;
}

inline int sgn(int b0, int b1, int b2) {
    return (b0 + b1 + b2) % 2 == 1 ? 1 : -1;
}

ll sum(int x1, int x2, int y1, int y2, int z1, int z2) {
    int dx = x2-x1+1, dy = y2-y1+1, dz = z2-z1+1;

    ll ans = 0;
    _rep(i, 0, 7) {
        int b0, b1, b2;
        expand(i, b0, b1, b2);
        ans -= S[x2-b0*dx][y2-b1*dy][z2-b2*dz] * sgn(b0, b1, b2);
    }
    return ans;
}

void prework() {
    _rep(x, 1, a) _rep(y, 1, b) _rep(z, 1, c) _rep(i, 1, 7) {
        int b0, b1, b2;
        expand(i, b0, b1, b2);
        S[x][y][z] += S[x-b0][y-b1][z-b2] * sgn(b0, b1, b2);
    }
}

void solve() {
    ll ans = -inf;
    _rep(x1, 1, a) _rep(x2, x1, a) _rep(y1, 1, b) _rep(y2, y1, b) {
        ll M = 0;
        _rep(z, 1, c) {
            ll s = sum(x1, x2, y1, y2, 1, z);
            chmax(ans, s - M);
            chmin(M, s);
        }
    }
    printf("%lld\n", ans);
}

void init() {
    memset(S, 0, sizeof(S));
}

int main() {
    freopen("input.txt", "r", stdin);
    int kase;
    cin >> kase;

    while (kase--) {
        scanf("%d%d%d", &a, &b, &c);
        init();

        // get data
        _rep(x, 1, a) _rep(y, 1, b) _rep(z, 1, c) scanf("%lld", &S[x][y][z]);

        // then prework and solve
        prework();
        solve();
        if (kase) printf("\n");
    }
}