矩陣快速冪

struct Matrix
{
    ll m[sz][sz];
};
Matrix Mul(Matrix a,Matrix b)
{
    Matrix c;
    memset(c.m,0,sizeof(c.m));
    for(int i=0; i<sz; i++)
        for(int j=0; j<sz; j++)
            for(int k=0; k<sz; k++)
            {
                if(a.m[i][k]==0||b.m[k][j]==0) continue;
                c.m[i][j]=(c.m[i][j]+a.m[i][k]*b.m[k][j]+mod)%mod;
            }
    return c;
}
Matrix fastm(Matrix res, Matrix a,ll n)
{
    while(n)
    {
        if(n&1)
            res = Mul(res,a);
        n>>=1;
        a = Mul(a,a);
    }
    return res;
}
Matrix init()//關係陣
{
    Matrix pp;
    return pp;
}