local read = setmetatable({}, {__index = function(t, k) local a = {} for i=1,#k do table.insert(a, '*'..string.sub(k, i, i)) end local r = io.read local u = table.unpack or unpack return function() return r(u(a)) end end})
read.N = function(N) local t={} for i=1,N do t[i]=read.n() end return t end
string.totable = function(s) local t={} local u=string.sub for i=1,#s do t[i] = u(s, i, i) end return t end
string.split = function(s) local t={} for w in string.gmatch(s, "[^%s]+") do table.insert(t, w) end return (table.unpack or unpack)(t) end
local function array(dimensi0n, default_val) assert(type(default_val) ~= 'table') local n=dimensi0n local m={}if default_val~=nil then m[1]={__index=function()return default_val end}end for i=2,n do m[i]={__index=function(p, k)local c=setmetatable({},m[i-1])rawset(p,k,c)return c end}end return setmetatable({},m[n])end
local function tostringxx(o, depth) depth = depth or 0 if depth > 10 then return "<too deep!>" end if o == _G then return "<_G>" end local indent0 = (" "):rep((depth) * 2) local indent1 = (" "):rep((depth+1) * 2) local indent2= (" "):rep((depth+2) * 2) if type(o) == 'table' then local keys = {} local types = {} for k in pairs(o) do types[type(k)] = true table.insert(keys, k) end local types_count = 0 local lasttype for k in pairs(types) do types_count = types_count + 1 lasttype = k end if types_count == 1 and (lasttype == 'string' or lasttype == 'number') then table.sort(keys) end local inside = {} for i=1,#keys do local k = keys[i] local v = o[k] if type(k) == 'string' then k = string.format('%q', k) end table.insert(inside, indent1 .. '['..tostring(k)..'] = ' .. tostringxx(v, depth + 1)) end return '{\n' .. table.concat(inside, ',\n') .. '\n' .. indent0 .. '}' else if type(o) == 'string' then o = string.format('%q', o) end return tostring(o) end end
local function richtraceback() local x = 2 while true do local info = debug.getinfo(x) if not info then break end local fname = '<' .. info.short_src .. ":" .. info.linedefined .. ">" if info.name then fname = info.name end print(info.short_src .. ":" .. info.currentline .. ": in " .. ("%q"):format(fname)) print(" LOCALS:") local p = 1 while true do local name, val = debug.getlocal(x,p) if not name then break end print(" " .. name .. ": " .. tostringxx(val, 3)) p = p + 1 end print(" UPVALUES:") for p=1,info.nups do local name, val = debug.getupvalue(info.func,p) if not name then break end print(" " .. name .. ": " .. tostringxx(val, 3)) end x = x + 1 end end
local function myassert(b) if not b then richtraceback() error("assertion failed") end end 
--
local DBG = false
local insert = table.insert
local function getkeys(t)
    local keys = {}
    for k,v in pairs(t) do
        insert(keys, k)
    end
    table.sort(keys)
    return keys
end

local function dbgpr(...)
    if DBG then
        io.write("[dbg]")
        print(...)
    end
end
--
local N = read.nl()
local X, Y, U = {},{},{}
local yy = {}
local xx = {}
local rr = {} -- right down
local ll = {} -- left down
local function push(tt, p, e)
    if not tt[p] then
        tt[p] = {}
    end
    insert(tt[p], e)
end
for i=1,N do
    X[i], Y[i], U[i] = read.nnl()
    U[i] = U[i]:sub(2,2)
    local e = i
    push(yy, Y[i], e)
    push(xx, X[i], e)
    local rrp = X[i] + Y[i]
    push(rr, rrp, e)
    local llp = X[i] - Y[i]
    push(ll, llp, e)
end
--richtraceback()
local INF = 10^18
local nearest_crash = INF
local function f1(name, tt, inv, fw, bk, sp)
    local ttk = getkeys(tt)
    for _,w in ipairs(ttk) do
        local t = tt[w]
        dbgpr("on same " .. name , w)
        local inttk = {}
        for _,i in ipairs(t) do
            if U[i] == fw or U[i] == bk then
                insert(inttk, {inv[i], i, U[i]})
            end
        end
        table.sort(inttk, function (a1, a2)
            return a1[1] < a2[1]
        end)
        local state = 0
        local recentfwinv = -200000
        for _,ee in ipairs(inttk) do
            local i = ee[2]
            if U[i] == fw or U[i] == bk then
                dbgpr("plane #" .. i, "inv="..inv[i], "X="..X[i], "Y="..Y[i], U[i])
                if state == 0 then
                    if U[i] == fw then
                        state = 1
                        recentfwinv = inv[i]
                    end
                elseif state == 1 then
                    if U[i] == fw then
                        recentfwinv = inv[i]
                    elseif U[i] == bk then
                        local d = inv[i] - recentfwinv
                        nearest_crash = math.min(nearest_crash, d * sp)
                        dbgpr("crash!", i, nearest_crash)
                    end
                end
            end
        end
    end
    
end
f1('Y', yy, X, 'R', 'L', 5)
f1('X', xx, Y, 'U', 'D', 5)
f1('rr', rr, X, 'R', 'U', 10)
f1('rr', rr, X, 'D', 'L', 10)
f1('ll', ll, X, 'U', 'L', 10)
f1('ll', ll, X, 'R', 'D', 10)

if nearest_crash == INF then
    print("SAFE")
else
    print(nearest_crash)
end