import macros;macro ImportExpand(s:untyped):untyped = parseStmt($s[2])
when not defined(second_compile):
    const tmp = staticExec("nim cpp -d:danger --mm:refc -o:a.out -d:second_compile Main.nim")
    static:
        echo tmp
        quit()
ImportExpand "cplib/tmpl/sheep.nim" <=== "when not declared CPLIB_TMPL_SHEEP:\n    const CPLIB_TMPL_SHEEP* = 1\n    {.warning[UnusedImport]: off.}\n    {.hint[XDeclaredButNotUsed]: off.}\n    import algorithm\n    import sequtils\n    import tables\n    import macros\n    import math\n    import sets\n    import strutils\n    import strformat\n    import sugar\n    import heapqueue\n    import streams\n    import deques\n    import bitops\n    import std/lenientops\n    import options\n    #入力系\n    proc scanf(formatstr: cstring){.header: \"<stdio.h>\", varargs.}\n    proc getchar(): char {.importc: \"getchar_unlocked\", header: \"<stdio.h>\", discardable.}\n    proc ii(): int {.inline.} = scanf(\"%lld\\n\", addr result)\n    proc lii(N: int): seq[int] {.inline.} = newSeqWith(N, ii())\n    proc si(): string {.inline.} =\n        result = \"\"\n        var c: char\n        while true:\n            c = getchar()\n            if c == ' ' or c == '\\n':\n                break\n            result &= c\n    #chmin,chmax\n    template `max=`(x, y) = x = max(x, y)\n    template `min=`(x, y) = x = min(x, y)\n    #bit演算\n    proc `%`*(x: int, y: int): int =\n        result = x mod y\n        if y > 0 and result < 0: result += y\n        if y < 0 and result > 0: result += y\n    proc `//`*(x: int, y: int): int{.inline.} =\n        result = x div y\n        if y > 0 and result * y > x: result -= 1\n        if y < 0 and result * y < x: result -= 1\n    proc `%=`(x: var int, y: int): void = x = x%y\n    proc `//=`(x: var int, y: int): void = x = x//y\n    proc `**`(x: int, y: int): int = x^y\n    proc `**=`(x: var int, y: int): void = x = x^y\n    proc `^`(x: int, y: int): int = x xor y\n    proc `|`(x: int, y: int): int = x or y\n    proc `&`(x: int, y: int): int = x and y\n    proc `>>`(x: int, y: int): int = x shr y\n    proc `<<`(x: int, y: int): int = x shl y\n    proc `~`(x: int): int = not x\n    proc `^=`(x: var int, y: int): void = x = x ^ y\n    proc `&=`(x: var int, y: int): void = x = x & y\n    proc `|=`(x: var int, y: int): void = x = x | y\n    proc `>>=`(x: var int, y: int): void = x = x >> y\n    proc `<<=`(x: var int, y: int): void = x = x << y\n    proc `[]`(x: int, n: int): bool = (x and (1 shl n)) != 0\n    #便利な変換\n    proc `!`(x: char, a = '0'): int = int(x)-int(a)\n    #定数\n    #[ include cplib/utils/constants ]#\n    when not declared CPLIB_UTILS_CONSTANTS:\n        const CPLIB_UTILS_CONSTANTS* = 1\n        const INF32*: int32 = 100100111.int32\n        const INF64*: int = int(3300300300300300491)\n    const INF = INF64\n    #converter\n\n    #range\n    iterator range(start: int, ends: int, step: int): int =\n        var i = start\n        if step < 0:\n            while i > ends:\n                yield i\n                i += step\n        elif step > 0:\n            while i < ends:\n                yield i\n                i += step\n    iterator range(ends: int): int = (for i in 0..<ends: yield i)\n    iterator range(start: int, ends: int): int = (for i in\n            start..<ends: yield i)\n\n    #joinが非stringでめちゃくちゃ遅いやつのパッチ\n    proc join*[T: not string](a: openArray[T], sep: string = \"\"): string = a.mapit($it).join(sep)\n"
ImportExpand "cplib/modint/modint.nim" <=== "when not declared CPLIB_MODINT_MODINT:\n    const CPLIB_MODINT_MODINT* = 1\n    #[ include cplib/modint/barrett_impl ]#\n    when not declared CPLIB_MODINT_MODINT_BARRETT:\n        const CPLIB_MODINT_MODINT_BARRETT* = 1\n        when compileOption(\"mm\", \"orc\") or compileOption(\"mm\", \"arc\"):\n            {.fatal: \"Plese Use refc\".}\n        import std/macros\n        type StaticBarrettModint*[M: static[uint32]] = object\n            a: uint32\n        type DynamicBarrettModint*[M: static[uint32]] = object\n            a: uint32\n        type BarrettModint* = StaticBarrettModint or DynamicBarrettModint\n    \n        proc get_im*(M: uint32): uint = cast[uint](-1) div M + 1\n        func get_param*[M: static[uint32]](self: typedesc[DynamicBarrettModint[M]]): ptr[tuple[M, im: uint]] =\n            {.cast(noSideEffect).}:\n                var p {.global.}: tuple[M, im: uint] = (998244353u, get_im(998244353u32))\n                return p.addr\n        template get_M*(T: typedesc[BarrettModint]): uint =\n            when T is StaticBarrettModint: T.M.uint\n            else: (get_param(T))[].M.uint\n        proc setMod*[T: static[uint32]](self: typedesc[DynamicBarrettModint[T]], M: SomeInteger or SomeUnsignedInt) =\n            (get_param(self))[] = (M: M.uint, im: get_im(M.uint32))\n    \n        template umod*[T: BarrettModint](self: typedesc[T] or T): uint32 =\n            when self is typedesc:\n                when self is StaticBarrettModint: self.M\n                else: cast[uint32](((get_param(self))[]).M)\n            else: T.umod\n        template `mod`*[T: BarrettModint](self: typedesc[T] or T): int32 = (T.umod).int32\n        {.emit: \"\"\"\n        #include <cstdio>\n        inline unsigned long long calc_mul(const unsigned long long &a, const unsigned long long &b) {\n            return (unsigned long long)(((__uint128_t)(a) * b) >> 64);\n        }\n        \"\"\".}\n        proc calc_mul*(a, b: culonglong): culonglong {.importcpp: \"calc_mul(#, #)\", nodecl, inline.}\n        proc rem*(T: typedesc[BarrettModint], a: uint): uint32 =\n            when T is StaticBarrettModint:\n                const im = get_im(T.M)\n                const M = get_M(T)\n                var x = (calc_mul(cast[culonglong](a), cast[culonglong](im))).uint\n                var r = a - x * M\n                if M <= r: r += M\n                return cast[uint32](r)\n            else:\n                var p = get_param(T)[]\n                var x = (calc_mul(cast[culonglong](a), cast[culonglong](p.im))).uint\n                var r = a - x * p.M\n                if p.M <= r: r += p.M\n                return cast[uint32](r)\n        proc init*(T: typedesc[BarrettModint], a: T or SomeInteger): auto =\n            when a is T: return a\n            else:\n                if a in 0..<T.mod.int: return T(a: a.uint32)\n                var a = a mod T.mod.int\n                if a < 0: a += T.mod.int\n                return T(a: a.uint32)\n    \n        proc `-`*[T: BarrettModint](a: T): T = T(a: T.umod - a.a)\n        proc `+=`*[T: BarrettModint](a: var T, b: T or SomeInteger) =\n            a.a += init(T, b).a\n            if a.a >= T.umod: a.a -= T.umod\n        proc `-=`*[T: BarrettModint](a: var T, b: T or SomeInteger) =\n            a.a -= init(T, b).a\n            if a.a >= T.umod: a.a += T.umod\n        proc `*=`*[T: BarrettModint] (a: var T, b: T or SomeInteger) =\n            a.a = rem(T, (a.a).uint * (init(T, b).a).uint)\n        proc inv*[T: BarrettModint](x: T): T =\n            assert x.val != 0\n            var x: int32 = int32(x.val)\n            var y: int32 = T.mod\n            var u = 1i32\n            var v, t = 0i32\n            while y > 0:\n                t = x div y\n                x -= t * y\n                u -= t * v\n                swap(x, y)\n                swap(u, v)\n            return init(T, u)\n        proc `/=`*[T: BarrettModint](a: var T, b: T or SomeInteger) = a *= init(T, b).inv\n        proc val*(a: BarrettModint): int = a.a.int\n        macro declarStaticBarrettModint*(name, M) =\n            let converter_name = ident(\"to\" & $`name`)\n            quote do:\n                type `name`* = StaticBarrettModint[`M`]\n                converter `converter_name`*(a: int): StaticBarrettModint[`M`] = init(StaticBarrettModint[`M`], a)\n        macro declarDynamicBarrettModint*(name, id) =\n            let converter_name = ident(\"to\" & $`name`)\n            quote do:\n                type `name`* = DynamicBarrettModint[`id`]\n                converter `converter_name`*(a: int): DynamicBarrettModint[`id`] = init(DynamicBarrettModint[`id`], a)\n    #[ include cplib/modint/montgomery_impl ]#\n    when not declared CPLIB_MODINT_MODINT_MONTGOMERY:\n        const CPLIB_MODINT_MODINT_MONTGOMERY* = 1\n        when compileOption(\"mm\", \"orc\") or compileOption(\"mm\", \"arc\"):\n            {.fatal: \"Plese Use refc\".}\n        import std/macros\n        type StaticMontgomeryModint*[M: static[uint32]] = object\n            a: uint32\n        type DynamicMontgomeryModint*[M: static[uint32]] = object\n            a: uint32\n        type MontgomeryModint* = StaticMontgomeryModint or DynamicMontgomeryModint\n    \n        proc get_r*(M: uint32): uint32 =\n            result = M\n            for _ in 0..<4: result *= 2u32 - M * result\n        proc get_n2*(M: uint32): uint32 = uint32((not uint(M - 1u32)) mod uint(M))\n        proc check_params(M, r: uint32) =\n            assert M < (1u32 shl 30), \"invalid mod >= 2^30\"\n            assert (M and 1u32) == 1u32, \"invalid mod % 2 == 0\"\n            assert r * M == 1, \"r * mod != 1\"\n        func get_param*[M: static[uint32]](self: typedesc[DynamicMontgomeryModint[M]]): ptr[tuple[M, r, n2: uint32]] =\n            {.cast(noSideEffect).}:\n                var p {.global.}: tuple[M, r, n2: uint32] = (998244353u32, get_r(998244353u32), get_n2(998244353u32))\n                return p.addr\n        template get_M*(T: typedesc[MontgomeryModint]): uint32 =\n            when T is StaticMontgomeryModint: T.M\n            else: (get_param(T))[].M\n        proc setMod*[T: static[uint32]](self: typedesc[DynamicMontgomeryModint[T]], M: SomeInteger or SomeUnsignedInt) =\n            var r = get_r(M.uint32)\n            var n2 = get_n2(M.uint32)\n            var p = (M.uint32, r, n2)\n            (get_param(self))[] = p\n            check_params(M.uint32, r)\n    \n        template umod*[T: MontgomeryModint](self: typedesc[T] or T): uint32 =\n            when self is typedesc:\n                when self is StaticMontgomeryModint: self.M\n                else: ((get_param(self))[]).M\n            else: T.umod\n        template `mod`*[T: MontgomeryModint](self: typedesc[T] or T): int32 = (T.umod).int32\n    \n        func reduce(T: typedesc[MontgomeryModint], b: uint): uint32 =\n            when T is StaticMontgomeryModint:\n                const r = get_r(T.M)\n                return cast[uint32]((b + uint(cast[uint32](b) * (not (r - 1u32))) * T.M) shr 32)\n            else:\n                var p = (get_param(T))[]\n                return cast[uint32]((b + uint(cast[uint32](b) * (not (p.r - 1u32))) * p.M) shr 32)\n        proc init*(T: typedesc[MontgomeryModint], a: T or SomeInteger): auto =\n            when a is T: return a\n            elif T is StaticMontgomeryModint:\n                const r = get_r(T.M)\n                const n2 = get_n2(T.M)\n                check_params(T.M, r)\n                var ai = reduce(T, uint(a.int32 mod T.M.int32 + T.M.int32) * n2)\n                result = StaticMontgomeryModint[T.M](a: ai)\n            elif T is DynamicMontgomeryModint:\n                var p = (get_param(T))[]\n                var ai = reduce(T, uint(a.int32 mod p.M.int32 + p.M.int32) * p.n2)\n                result = DynamicMontgomeryModint[T.M](a: ai)\n    \n        proc `+=`*[T: MontgomeryModint](a: var T, b: T or SomeInteger) =\n            a.a += init(T, b).a - T.get_M * 2u32\n            if cast[int32](a.a) < 0i32: a.a += T.get_M * 2u32\n        proc `-=`*[T: MontgomeryModint](a: var T, b: T or SomeInteger) =\n            a.a -= init(T, b).a\n            if cast[int32](a.a) < 0i32: a.a += T.get_M * 2u32\n        proc val*[T: MontgomeryModint](a: T): int =\n            result = reduce(T, a.a).int\n            if result.uint32 >= T.get_M: result -= T.get_M.int\n    \n        proc `-`*[T: MontgomeryModint](a: T): T = init(T, 0) - a\n        proc `*=`*[T: MontgomeryModint] (a: var T, b: T or SomeInteger) = a.a = reduce(T, uint(a.a) * init(T, b).a)\n        proc inv*[T: MontgomeryModint](x: T): T =\n            assert x.val != 0\n            var x: int32 = int32(x.val)\n            var y: int32 = T.mod\n            var u = 1i32\n            var v, t = 0i32\n            while y > 0:\n                t = x div y\n                x -= t * y\n                u -= t * v\n                swap(x, y)\n                swap(u, v)\n            return init(T, u)\n        proc `/=`*[T: MontgomeryModint](a: var T, b: T or SomeInteger) = a *= init(T, b).inv\n    \n        macro declarStaticMontgomeryModint*(name, M) =\n            let converter_name = ident(\"to\" & $`name`)\n            quote do:\n                type `name`* = StaticMontgomeryModint[`M`]\n                converter `converter_name`*(a: int): StaticMontgomeryModint[`M`] = init(StaticMontgomeryModint[`M`], a)\n        macro declarDynamicMontgomeryModint*(name, id) =\n            let converter_name = ident(\"to\" & $`name`)\n            quote do:\n                type `name`* = DynamicMontgomeryModint[`id`]\n                converter `converter_name`*(a: int): DynamicMontgomeryModint[`id`] = init(DynamicMontgomeryModint[`id`], a)\n    import std/math\n    import std/algorithm\n    #[ import cplib/math/isqrt ]#\n    when not declared CPLIB_MATH_ISQRT:\n        const CPLIB_MATH_ISQRT* = 1\n        proc isqrt*(n: int): int =\n            var x = n\n            var y = (x + 1) shr 1\n            while y < x:\n                x = y\n                y = (x + n div x) shr 1\n            return x\n    declarStaticMontgomeryModint(modint998244353_montgomery, 998244353u32)\n    declarStaticMontgomeryModint(modint1000000007_montgomery, 1000000007u32)\n    declarDynamicMontgomeryModint(modint_montgomery, 1u32)\n    declarStaticBarrettModint(modint998244353_barrett, 998244353u32)\n    declarStaticBarrettModint(modint1000000007_barrett, 1000000007u32)\n    declarDynamicBarrettModint(modint_barrett, 1u32)\n    func `+`*(a, b: MontgomeryModint or BarrettModint): auto = (result = a; result += b)\n    func `-`*(a, b: MontgomeryModint or BarrettModint): auto = (result = a; result -= b)\n    func `*`*(a, b: MontgomeryModint or BarrettModint): auto = (result = a; result *= b)\n    func `/`*(a, b: MontgomeryModint or BarrettModint): auto = (result = a; result /= b)\n    func `+`*(a: MontgomeryModint or BarrettModint, b: SomeInteger): auto = (result = a; result += b)\n    func `-`*(a: MontgomeryModint or BarrettModint, b: SomeInteger): auto = (result = a; result -= b)\n    func `*`*(a: MontgomeryModint or BarrettModint, b: SomeInteger): auto = (result = a; result *= b)\n    func `/`*(a: MontgomeryModint or BarrettModint, b: SomeInteger): auto = (result = a; result /= b)\n    func `+`*(a: SomeInteger, b: MontgomeryModint or BarrettModint): auto = b + a\n    func `-`*(a: SomeInteger, b: MontgomeryModint or BarrettModint): auto = b - a\n    func `*`*(a: SomeInteger, b: MontgomeryModint or BarrettModint): auto = b * a\n    func `/`*(a: SomeInteger, b: MontgomeryModint or BarrettModint): auto = b / a\n    proc `/`*[ModInt: MontgomeryModint or BarrettModint](a: ModInt, b: static int): auto =\n        const tmp = init(Modint, b).inv\n        return a * tmp\n    func pow*(a: MontgomeryModint or BarrettModint, n: int): auto =\n        result = init(typeof(a), 1)\n        var a = a\n        var n = n\n        while n > 0:\n            if (n and 1) == 1: result *= a\n            a *= a\n            n = (n shr 1)\n    func `$`*(a: MontgomeryModint or BarrettModint): string = $(a.val)\n    proc estimate_rational*(a: MontgomeryModint or BarrettModint, ub: int = isqrt(typeof(a).mod)): string =\n        var v: seq[tuple[s, n, d: int]]\n        for d in 1..ub:\n            var n = (a * d).val\n            if n * 2 > a.mod:\n                n = - (a.mod - n)\n            if gcd(n, d) > 1: continue\n            v.add((n.abs + d, n, d))\n        v.sort\n        return $v[0].n & \"/\" & $v[0].d\n"


type mint = modint998244353_barrett
var N = ii()
var S = si()
#0:l 1:r 2:u
var DP = newSeqWith(N+1,(mint(0),mint(0),mint(0)))
DP[0][2] = 1

for i in range(N):
    if S[i] == 'L':
        DP[i+1][0] += DP[i][0]+DP[i][2]
    elif S[i] == 'R':
        DP[i+1][1] += DP[i][0]+DP[i][1]+DP[i][2]
    elif S[i] == 'U':
        DP[i+1][2] += DP[i][0]+DP[i][1]+DP[i][2]
    else:
        DP[i+1][0] += DP[i][0]+DP[i][2]
        DP[i+1][1] += DP[i][0]+DP[i][1]+DP[i][2]
        DP[i+1][2] += DP[i][0]+DP[i][1]+DP[i][2]

echo DP[^1][0] + DP[^1][1] + DP[^1][2]