/in/foo.cc:5:13: error: stray '\357' in program
    int k,L,R，sum=0;
             ^
/in/foo.cc:5:14: error: stray '\274' in program
    int k,L,R，sum=0;
              ^
/in/foo.cc:5:15: error: stray '\214' in program
    int k,L,R，sum=0;
               ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:5:16: error: expected initializer before 'sum'
    int k,L,R，sum=0;
                ^~~
/in/foo.cc:6:13: error: 'R' was not declared in this scope
  cin>>k>>L>>R;
             ^
/in/foo.cc:10:4: error: 'sum' was not declared in this scope
    sum+=i;
    ^~~
/in/foo.cc:12:9: error: 'sum' was not declared in this scope
   cout<<sum;
         ^~~