/in/foo.cc: In function 'int main()':
/in/foo.cc:21:14: error: 'n' was not declared in this scope; did you mean 'yn'?
   21 |         cin>>n>>e>>s;
      |              ^
      |              yn
/in/foo.cc:26:25: error: 'f' was not declared in this scope
   26 |                         f[i]=max(f[i],f[j]+add(i,j));
      |                         ^
/in/foo.cc:27:15: error: 'f' was not declared in this scope
   27 |         cout<<f[n]<<endl;;
      |               ^
/in/foo.cc: In function 'int add(int, int)':
/in/foo.cc:14:1: warning: control reaches end of non-void function [-Wreturn-type]
   14 | }
      | ^