Pi/4=1-1/3+1/5-1/7+.
A=1/5-1/3/5^3+1/5/5^5-1/7/5^7+1/9/5^9-1/11/5^11+.
B=1/239-1/3/239^3+1/5/238^5-1/7/239^7+1/9/239^9-1/11/239^11+...
Pi/4=4A-B
Pi/4=1-1/3+1/5-1/7+.
A=1/5-1/3/5^3+1/5/5^5-1/7/5^7+1/9/5^9-1/11/5^11+.
B=1/239-1/3/239^3+1/5/238^5-1/7/239^7+1/9/239^9-1/11/239^11+...
Pi/4=4A-B