View Compilation Error

0_0_37118240_5143.cpp: In function 'int main()':
0_0_37118240_5143.cpp:23:18: error: expected primary-expression before ';' token
     int y, sum = ;
                  ^
0_0_37118240_5143.cpp:32:38: error: expected primary-expression before ')' token
             sum = sum - ( ch - 'a'+  );
                                      ^
0_0_37118240_5143.cpp:36:37: error: expected primary-expression before ')' token
             sum = sum + (ch - 'A' + );
                                     ^