View Compilation Error

0_0_30318565_16551.cpp: In function 'int main()':
0_0_30318565_16551.cpp:26:63: error: invalid operands of types 'long long int' and '<unresolved overloaded function type>' to binary 'operator<<'
         cout<<(((n-1)*n/2)%1000000007-(ol(n)/2)*n%1000000007<<endl;
                                                               ^
0_0_30318565_16551.cpp:26:67: error: expected ')' before ';' token
         cout<<(((n-1)*n/2)%1000000007-(ol(n)/2)*n%1000000007<<endl;
                                                                   ^