View Compilation Error

0_0_31915428_15537.cpp: In function 'int main()':
0_0_31915428_15537.cpp:40:17: error: 'sum' was not declared in this scope
             if((sum[l]-sum[r])!=w)
                 ^
0_0_31915428_15537.cpp:48:13: error: 'sum' was not declared in this scope
             sum[fl]=-sum[l]+sum[r]+w;
             ^