答案是2.
计算结果：
Program :PiFast version 4.1,by Xavier Gourdon
Computation of 100000000 digits of Pi
Method used :Chudnovsky
Size of FFT :8192 K
Physical memory used :525137 K
Disk memory used :0.00 Meg
------------------------------------------------------------
Computation run information :
Start :Sun Jun 04 12:54:13 2006
End :Sun Jun 04 13:19:11 2006
Duration :1498.34 seconds
Pi with 100000000 digits :
Pi = 3.
1415926535 8979323846 2643383279 5028841971 6939937510 :50
5820974944 5923078164 0628620899 8628034825 3421170679 :100
.
6501675375 6332609852 3762615971 6259247683 5831887658 :99999750
4608008037 9562709698 7475571896 3659163731 5520304139 :99999800
1565422271 7752187699 9363665605 8378548054 8029802914 :99999850
8592592000 7320608799 3745194714 8463868800 9860046163 :99999900
9948682556 3967530560 3352869667 7734610718 4471868529 :99999950
7572203175 2074898161 1683139375 1497058112 0187751592 :100000000