View Compilation Error

0_0_35530799_10215.cpp: In function 'int main()':
0_0_35530799_10215.cpp:105:17: error: 'cal' was not declared in this scope
    cout << cal(r) << "\n";
                 ^
0_0_35530799_10215.cpp:107:16: error: 'cal' was not declared in this scope
   cout << cal(r) - cal(l - 1) << "\n";
                ^