foo.cc: In function ‘int main()’:
foo.cc:18:25: error: ‘f2’ was not declared in this scope; did you mean ‘f’?
   18 |                         f2[j]=max(f2[j],f2[j-v[i]]+w[i]);
      |                         ^~
      |                         f
foo.cc:21:15: error: ‘f2’ was not declared in this scope; did you mean ‘f’?
   21 |         cout<<f2[m]<<endl;
      |               ^~
      |               f