View Compilation Error

0_0_20475261_1336.cpp: In function 'int main()':
0_0_20475261_1336.cpp:36:25: error: 'sum' was not declared in this scope
                         sum++;
                         ^
0_0_20475261_1336.cpp:44:23: error: 'sum' was not declared in this scope
                 cout<<sum - 1<<endl;
                       ^