#include <bits/stdc++.h>

#define endl '\n'
#define TRACE(x) cerr << #x << " = " << x << endl
//#define LOCAL

using namespace std;
template<class T, class T1> inline bool chkmax(T &x, const T1 &y) { return x < y ? x = y, true : false; }
template<class T, class T1> inline bool chkmin(T &x, const T1 &y) { return x > y ? x = y, true : false; }

const int MAXN = 1024;
const int MAXM = 1024;

int m, b;

struct sequence {
    int seq[MAXM];

    void read() {
        for (int i = 0; i < m; i++) cin >> this->seq[i];
    }

    sequence operator +(const sequence &other) const {
        sequence ans;
        for (int i = 0; i < m; i++) ans.seq[i] = (this->seq[i] + other.seq[i]) % b;
        return ans;
    }

    sequence& operator +=(const sequence &other) {
        for (int i = 0; i < m; i++) this->seq[i] = (this->seq[i] + other.seq[i]) % b;
        return *this;
    }

    int get_sum() const {
        int ans = 0;
        for (int i = 0; i < m; i++) ans += this->seq[i] * this->seq[i];
        return ans;
    }
};

ostream& operator <<(ostream &os, const sequence &seq) {
    for (int i = 0; i < m; i++) os << seq.seq[i] << ' ';
    return os;
}

int n;
sequence a[MAXN];

void read() {
    cin >> n >> m >> b;
    for (int i = 0; i < n; i++) a[i].read();
}

int dp[MAXN];
int parent[MAXN];
sequence sum_sequences[MAXN];

void brute_force() {
    int best_mask = 0, best_sum = 0;
    sequence help;
    for (int mask = 1; mask < (1 << n); mask++) {
        for (int i = 0; i < m; i++) help.seq[i] = 0;
        for (int rmask = mask, idx = 0; rmask; rmask >>= 1, idx++) {
            if (rmask & 1) help = help + a[idx];
        }
        if (chkmax(best_sum, help.get_sum())) best_mask = mask;
    }
    cout << __builtin_popcount(best_mask) << endl;
    for (int idx = 1; best_mask; best_mask >>= 1, idx++) {
        if (best_mask & 1) cout << idx << endl;
    }
}

void smart_brute_force() {
    int best_mask = 0, best_sum = 0, best_offset;
    sequence help;
    int jump = n >= 20 ? n / 20 : n;
    for (int mask = 1; mask < (1 << 14); mask++) {
        for (int offset = 0; offset < n; offset += jump) {
            for (int i = 0; i < m; i++) help.seq[i] = 0;
            for (int rmask = mask, idx = offset; rmask; rmask >>= 1, idx++) {
                if (rmask & 1) help = help + a[idx];
            }
            if (chkmax(best_sum, help.get_sum())) {
                best_mask = mask;
                best_offset = offset;
            }
        }
    }
    cout << __builtin_popcount(best_mask) << endl;
    for (int idx = best_offset; best_mask; best_mask >>= 1, idx++) {
        if (best_mask & 1) cout << (idx + 1) << endl;
    }
}

void solve() {
    if (n <= 20) {
        brute_force();
        return;
    }
    if (n <= 200) {
        smart_brute_force();
        return;
    }
    dp[0] = a[0].get_sum();
    parent[0] = -1;
    sum_sequences[0] = a[0];
    sequence help;
    int max_idx = 0, max_dp = dp[0];
    for (int i = 1; i < n; i++) {
        int parent_idx = -1;
        int max_sum = 0;
        sequence max_seq;
        for (int j = i - 1; j >= 0; j--) {
            help = sum_sequences[j] + a[i];
            if (chkmax(max_sum, help.get_sum())) {
                parent_idx = j;
                max_seq = help;
            }
        }
        dp[i] = max_sum;
        parent[i] = parent_idx;
        sum_sequences[i] = max_seq;
        if (chkmax(dp[i], a[i].get_sum())) {
            parent[i] = -1;
            sum_sequences[i] = a[i];
        }
        if (chkmax(max_dp, dp[i])) max_idx = i;
        /*
        TRACE(i);
        TRACE(dp[i]);
        TRACE(parent[i]);
        cerr << sum_sequences[i] << endl;
        */
    }
    vector<int> ans;
    int curr = max_idx;
    while (curr != -1) {
        ans.push_back(curr);
        curr = parent[curr];
    }
    cout << ans.size() << endl;
    for (int idx : ans) cout << (idx + 1) << endl;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    #ifndef LOCAL
    freopen("subsetselection.in", "rt", stdin);
    freopen("subsetselection.out", "wt", stdout);
    #endif // LOCAL

    read();
    solve();

    return EXIT_SUCCESS;
}