The following text was obtained by applying the Vigenere encryption on a French language text

in which the spaces have been removed, Use the coincidence index to determine the length

of the key used and decrypt the text:

gmyxzoocxziancxktanmyolupjrztgxwshctzluibuic

yzwxyqtvqxzukibkotuxkagbknmimmzzajvjzampqyz

loinoiqknaumbknknvkaiakgwtnilvvzvqydmvjcximr

vzkilxzqtomrgqmdjrzyazvzmmyjgkoaknkuiaivknvvy