View Compilation Error

0_0_31222826_13454.cpp: In function 'int main()':
0_0_31222826_13454.cpp:22:27: error: 'A' was not declared in this scope
     while(scanf("%d%d%d",&A,&B,&n) != EOF){
                           ^
0_0_31222826_13454.cpp:22:30: error: 'B' was not declared in this scope
     while(scanf("%d%d%d",&A,&B,&n) != EOF){
                              ^
0_0_31222826_13454.cpp:29:19: error: cannot convert 'Matrix' to 'int' in assignment
         a.m[0][0] = a;
                   ^
0_0_31222826_13454.cpp:30:19: error: cannot convert 'Matrix' to 'int' in assignment
         a.m[0][1] = a;
                   ^