时间复杂度：O(N * M * P)

cin>>n>>m;
for(int i = 1;i <= n; i ++ )
    for(int j = 1; j <= m; j ++ )
        cin>>a[i][j];

cin>>p;
for(int i = 1; i <= m; i ++ )
    for(int j = 1; j <= p; j ++ )
       cin>>b[i][j];

for(int i = 1; i <= n; i ++ )
    for(int j = 1; j <= p; j ++ )
        for(int k = 1; k <= m; k ++ )
            c[i][j] + = a[i][k] * b[k][j];

for(int i = 1; i <= n; i ++ )
    for(int j = 1; j <= p; j ++ )
        cout<<c[i][j];