### A question about definition of a polynomial ring.

I am trying to define a polynomial ring as follows:

```
from sage.combinat import *
n=9
m=100
R = PolynomialRing(QQ,n*m,['x'+str(i)+str(j) for i in range(1,n+1) for j in range(1,m+1)])
```

It is ok with n=9, m=100. But when I change n, m to n=11, m=100. Then there is an error: ValueError: variable name 'x111' appears more than once

I would like to have n=100, m=1000. How to solve this problem? Thank you very much.