#include "bits/stdc++.h"
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vl = vector<ll>;
using vvi = vector<vi>;
using vvl = vector<vl>;
const int INF = 1 << 28;
const ll MOD = 1000000007;
template <class T>
bool chmax(T &a, const T &b) {
    return (a < b) ? (a = b, 1) : 0;
}
template <class T>
bool chmin(T &a, const T &b) {
    return (b < a) ? (a = b, 1) : 0;
}

template <size_t N, typename R>
struct SquareMatrix {
    using arr = array<R, N>;
    using mat = array<arr, N>;
    mat dat;

    SquareMatrix() {
        for (size_t i = 0; i < N; i++)
            for (size_t j = 0; j < N; j++)
                dat[i][j] = R::add_identity();
    }
    SquareMatrix &operator=(const SquareMatrix &a) {
        dat = a.dat;
        return (*this);
    }
    bool operator==(const SquareMatrix &a) const { return dat == a.dat; }

    size_t size() const { return N; };
    arr &operator[](size_t k) { return dat[k]; };
    const arr &operator[](size_t k) const { return dat[k]; };

    static SquareMatrix add_identity() { return SquareMatrix(); }
    static SquareMatrix mul_identity() {
        SquareMatrix res;
        for (size_t i = 0; i < N; i++)
            res[i][i] = R::mul_identity();
        return res;
    }

    SquareMatrix operator*(const SquareMatrix &B) const {
        SquareMatrix res;
        for (size_t i = 0; i < N; i++)
            for (size_t j = 0; j < N; j++)
                for (size_t k = 0; k < N; k++)
                    res[i][j] = res[i][j] + (dat[i][k] * B[k][j]);
        return res;
    }

    SquareMatrix operator+(const SquareMatrix &B) const {
        SquareMatrix res;
        for (size_t i = 0; i < N; i++)
            for (size_t j = 0; j < N; j++)
                res[i][j] = dat[i][j] + B[i][j];
        return res;
    }

    SquareMatrix pow(long long n) const {
        SquareMatrix a = *this, res = mul_identity();
        while (n) {
            if (n & 1)
                res = res * a;
            a = a * a;
            n >>= 1;
        }
        return res;
    }
};

struct mint {
    ll v;
    ll mod;
    mint() : v(0) {}
    mint(signed v, ll mod = MOD) : v(v), mod(mod) {}
    mint(ll t, ll mod = MOD) : mod(mod) {
        v = t % mod;
        if (v < 0)
            v += mod;
    }

    mint pow(ll k) {
        mint res(1), tmp(v);
        while (k) {
            if (k & 1)
                res *= tmp;
            tmp *= tmp;
            k >>= 1;
        }
        return res;
    }

    static mint add_identity() { return mint(0); }
    static mint mul_identity() { return mint(1); }

    mint inv() { return pow(mod - 2); }

    mint &operator+=(mint a) {
        v += a.v;
        if (v >= mod)
            v -= mod;
        return *this;
    }
    mint &operator-=(mint a) {
        v += mod - a.v;
        if (v >= mod)
            v -= mod;
        return *this;
    }
    mint &operator*=(mint a) {
        v = 1LL * v * a.v % mod;
        return *this;
    }
    mint &operator/=(mint a) { return (*this) *= a.inv(); }

    mint operator+(mint a) const { return mint(v) += a; };
    mint operator-(mint a) const { return mint(v) -= a; };
    mint operator*(mint a) const { return mint(v) *= a; };
    mint operator/(mint a) const { return mint(v) /= a; };

    mint operator-() const { return v ? mint(MOD - v) : mint(v); }

    bool operator==(const mint a) const { return v == a.v; }
    bool operator!=(const mint a) const { return v != a.v; }
    bool operator<(const mint a) const { return v < a.v; }
};

int main() {
    int n;
    ll k;
    cin >> n >> k;
    SquareMatrix<50, mint> mat;
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            int a;
            cin >> a;
            mat[i][j] = mint(a);
        }
    }
    SquareMatrix<50, mint> ret = SquareMatrix<50, mint>::mul_identity();
    while (k) {
        if (k & 1)
            ret = ret * mat;
        mat = mat * mat;
        k >>= 1;
    }
    mint total = 0;
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            total += ret[i][j];
        }
    }
    cout << total.v << "\n";
    return 0;
}

Measured memory_bytes: 384