View Compilation Error

0_0_13430567_2479.cpp: In function 'int main()':
0_0_13430567_2479.cpp:68:15: error: 'num2' was not declared in this scope
      c[i].num=num2-num1;
               ^
0_0_13430567_2479.cpp:68:20: error: 'num1' was not declared in this scope
      c[i].num=num2-num1;
                    ^