View Compilation Error

0_0_29216920_32403.cpp: In function 'int main()':
0_0_29216920_32403.cpp:44:23: error: 'l' was not declared in this scope
                if(sum[l]-sum[r]!=z)
                       ^
0_0_29216920_32403.cpp:44:30: error: 'r' was not declared in this scope
                if(sum[l]-sum[r]!=z)
                              ^