d=1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991
n=gets.to_i
d*=n
ds=d.to_s
if ds.length == 190
    print "0.",ds,"\n"
else
    diff=ds.length-190
    ds.insert(diff,".")
    print ds
end