View Compilation Error

0_0_21470916_18862.cpp: In function 'int cal(int, int)':
0_0_21470916_18862.cpp:10:15: error: 'm' was not declared in this scope
     int L=1,R=m;
               ^
0_0_21470916_18862.cpp:24:21: error: 'n' was not declared in this scope
             sum += (n - x + 1) * (y - L + 1) * (R - y + 1);
                     ^
0_0_21470916_18862.cpp:35:31: error: 'n' was not declared in this scope
         sum+=(y-L+1)*(R-y+1)*(n-x+1);
                               ^