source_file.cpp: In function ‘int main()’: source_file.cpp:15:31: error: ‘end1’ was not declared in this scope cout <<"Sum

Question

Please someone tell me what this is

Answer 1

https://www.sololearn.com/discuss/333866/?ref=app
https://www.sololearn.com/discuss/1316935/?ref=app

Answer 2

Seems like bad spelling.
endl (lowercase L at the end) means a new line
end1 (number one at the end) does not mean anything