{模板}打包矩阵乘法

struct Matrix{    int a[M][M];    Matrix() {}    Matrix(int val)    {        memset(a,0,sizeof a);        for(int i=0;i<=tot;i++)            a[i][i]=val;    }    int* operator [] (int i)    {        return a[i];    }    friend Matrix operator * (Matrix x,Matrix y)    {        Matrix z(0);        for(int i=0;i<=tot;i++)            for(int j=0;j<=tot;j++)                for(int k=0;k<=tot;k++)                    (z[i][j]+=(long long)x[i][k]*y[k][j]%MOD)%=MOD;        return z;    }    friend Matrix Quick_Power(Matrix x,int y)    {        Matrix re(1);        while(y)        {            if(y&1) re=re*x;            x=x*x; y>>=1;        }        return re;    }}