n = io.read('*n')
_, str = io.read('*l'), io.read('*l')

function b2i(b) if b then return 1 else return 0 end end
function check(s1, s2)
    local s = { s1, s2 }
    for i = 3, n do
        s[i] = s[i - 1] ~ s[i - 2] ~ b2i(str:sub(i - 1, i - 1) == 'x')
    end
    if s1 == (s[n] ~ s[n - 1] ~ b2i(str:sub(n, n) == 'x')) and
        s2 == (s[1] ~ s[n] ~ b2i(str:sub(1, 1) == 'x'))
    then
        return s
    end
end
function print_tab(t)
    for i = 1, #t do if t[i] == 0 then io.write('S') else io.write('W') end end
    io.write('\n')
end

s = check(0, 0); if s ~= nil then print_tab(s) return end
s = check(0, 1); if s ~= nil then print_tab(s) return end
s = check(1, 0); if s ~= nil then print_tab(s) return end
s = check(1, 1); if s ~= nil then print_tab(s) return end
print('-1')
