The last digit for 11^x would always be 1

The last digits for 7^x follows a pattern of 7,9,3,1... so 7^2004 should end in 1

The last digits for 13^x follows a pattern of 3,9,7,1... so 13^2005 should end in 3

So the final product should end in 1*1*3 = 3

This sounds too easy... i might be wrong !!!