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```#include<bits/stdc++.h>
using namespace std;
typedef long long ll ;
typedef   vector<vector<ll>> Matrix;
#define int long long
int MAX_N;
ll MOD=1e9+7;
ll mod(ll x,ll y)
{
return (x)%MOD;
}
Matrix matMul(Matrix a, Matrix b) {
// normally O(n^3)
Matrix ans(MAX_N,vector<ll>(MAX_N));
// but O(1) as n = 2
for (int i = 0; i < MAX_N; ++i)
for (int j = 0; j < MAX_N; ++j)
ans[i][j] = 0;
for (int i = 0; i < MAX_N; ++i)
for (int k = 0; k < MAX_N; ++k) {
if (a[i][k] == 0) continue;
// optimization
for (int j = 0; j < MAX_N; ++j) {
ans[i][j] += mod(a[i][k], MOD) * mod(b[k][j], MOD);
ans[i][j] = mod(ans[i][j], MOD); // modular arithmetic
}
}
return ans;
}
Matrix matPow(Matrix base, int p) {
Matrix ans(MAX_N,vector<ll>(MAX_N));
for (int i = 0; i < MAX_N; ++i)
for (int j = 0; j < MAX_N; ++j)
ans[i][j] = (i == j);
while (p) {
if (p&1)
ans = matMul(ans, base);
base = matMul(base, base);
p >>= 1;
}
return ans;
}
signed main()
{
int n,k;
cin>>n>>k;
MAX_N=n;
Matrix v(n,vector<ll>(n));
for (int i=0;i<n;i++)
{
for (int j=0;j<n;j++)
cin>>v[i][j];
}
Matrix ans=matPow(v,k);
ll output=0;
for (int i=0;i<n;i++)
{
for (int j=0;j<n;j++)
{
output+=ans[i][j];
output%=MOD;
}
}
cout<<output;
}```