#(2^((2^(79-1))-1))*(2-(2^-8388528))
from decimal import *
getcontext().prec = 100
from decimal import localcontext
with localcontext() as ctx:
    print(ctx.Emax) # デフォルトの指数上限は999999なので、今回の計算だと足りない
    ctx.Emax = 999999999999999999999999 # 指数上限を増やす
    s = ctx.power(2,302231454903657293676543)
    print(s)
    w = ctx.power(2,-8388528)
    print(w)
    t = (s * 2 - s * w)
    print(t)
    #必要に応じて有効桁を調整する
    format_str = "{:.1e}".format(t)
    print(format_str)

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