[TestMethod1]
na=4
nb=4
nExpect=16
[TestMethod2]
na=3
nb=7
nExpect=21
[TestMethod3]
na=3
nb=5
nExpect=15
[TestMethod4]
na=2147483647
nb=2
nExpect=4294967294
[TestMethod5]
na=2147483647
nb=10
nExpect=21474836470