/in/foo.cc: In function 'int main()':
/in/foo.cc:9:13: error: redeclaration of 'int i'
    9 |         int i=n;
      |             ^
/in/foo.cc:7:13: note: 'int i' previously declared here
    7 |     for(int i=2;i<=n;i++)
      |             ^
/in/foo.cc:9:13: warning: unused variable 'i' [-Wunused-variable]
    9 |         int i=n;
      |             ^