View Compilation Error

0_0_35947365_13168.cpp: In function 'int main()':
0_0_35947365_13168.cpp:10:4: error: expected ';' before 'int'
    int sum=0;
    ^
0_0_35947365_13168.cpp:13:5: error: 'sum' was not declared in this scope
     sum+=k;
     ^
0_0_35947365_13168.cpp:15:10: error: 'sum' was not declared in this scope
    cout<<sum-n+1<<endl; 
          ^