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 log(log(log(log(x)))) = 0. 

Note that

log (1)  =  0

So.....this inplies that

 (log(log(log(x)))) = 1

And

log (10)  = 1

Which implies that

log (log (x) )   =   10

So   this implies that 

10^10  =  log x

x =  10^(10^10) = 10^(10000000000)