text <- c("TreeRULakeSunWater", "A B C RU D")
unknown_word <- gsub(".*Tree(\\w+)Lake.*", "\\1", text)
gsub(paste("[[:space:]]*(", unknown_word[[1]], ")[[:space:]]*", sep=""), " \n\\1 ", text)
dGV4dCA8LSBjKCJUcmVlUlVMYWtlU3VuV2F0ZXIiLCAiQSBCIEMgUlUgRCIpCnVua25vd25fd29yZCA8LSBnc3ViKCIuKlRyZWUoXFx3KylMYWtlLioiLCAiXFwxIiwgdGV4dCkKZ3N1YihwYXN0ZSgiW1s6c3BhY2U6XV0qKCIsIHVua25vd25fd29yZFtbMV1dLCAiKVtbOnNwYWNlOl1dKiIsIHNlcD0iIiksICIgXG5cXDEgIiwgdGV4dCkK