Matrica

#include<iostream>
using namespace std;

class Matrica{
    float a[10][10];
    int n;
    int m;
public:
    Matrica(){};
    Matrica& operator=(const Matrica &mat){
        this->n = mat.n;
        this->m = mat.m;
        for(int i=0; i < n; i++){
            for(int j=0; j < m; j++){
                this->a[i][j] = mat.a[i][j];
            }
        }
        return *this;
    }
    Matrica operator*(Matrica &mat){
        Matrica t(*this);
        for(int i = 0; i < n; ++i){
            for(int j = 0; j < mat.m; ++j){
                float temp = 0;
                for(int k = 0; k < m; ++k){
                    temp += a[i][k] * mat.a[k][j];
                }
                t.a[i][j] = temp;
            }
        }
        return t;
    }
    Matrica operator-(Matrica &mat){
        for(int i=0; i < n; i++){
            for(int j=0; j < m; j++){
                a[i][j] -= mat.a[i][j];
            }
        }
        return *this;
    }
    Matrica operator+(int num){
        for(int i=0; i < n; i++){
            for(int j=0; j < m; j++){
                a[i][j] += num;
            }
        }
        return *this;
    }
    friend istream &operator>>(istream &in, Matrica &mat){
        in >> mat.n >> mat.m;
        for(int i=0; i < mat.n; i++){
            for(int j=0; j < mat.m; j++){
                in >> mat.a[i][j];
            }
        }
        return in;
    }
    friend ostream &operator<<(ostream &o, const Matrica &mat){
        for(int i=0; i < mat.n; i++){
            for(int j=0; j < mat.m; j++){
               o << mat.a[i][j] << ' ';
            }
            o << endl;
        }
        return o;
    }
};

int main()
{
    Matrica A,B,C;
    cin>>A>>B>>C;
    Matrica D=B*C;
    Matrica R=A-D+2;
    cout<<R;
}