/in/foo.cc: In function 'int main()':
/in/foo.cc:8:8: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
  if(n=4)
        ^
/in/foo.cc:6:8: warning: unused variable 'i' [-Wunused-variable]
  int n,i,j,k,m;
        ^
/in/foo.cc:6:10: warning: unused variable 'j' [-Wunused-variable]
  int n,i,j,k,m;
          ^
/in/foo.cc:6:12: warning: unused variable 'k' [-Wunused-variable]
  int n,i,j,k,m;
            ^