View Compilation Error

0_0_31203840_4233.cpp: In function 'int main()':
0_0_31203840_4233.cpp:9:1: error: 'sum' was not declared in this scope
 sum += 5;
 ^
0_0_31203840_4233.cpp:10:19: error: 'sum' was not declared in this scope
    if (now < next)sum = sum + (next - now) * 6 + 5;
                   ^
0_0_31203840_4233.cpp:11:17: error: 'sum' was not declared in this scope
    if (now>next)sum = sum + (now - next) * 4 + 5;
                 ^
0_0_31203840_4233.cpp:14:18: error: 'sum' was not declared in this scope
   printf("%d\n", sum);
                  ^