#include using namespace std; using ll = long long; using uint = unsigned int; using ull = unsigned long long; #define rep(i,n) for(int i=0;i=0;i--) #define per1(i,n) for(int i=int(n);i>0;i--) #define all(c) c.begin(),c.end() #define si(x) int(x.size()) #define pb emplace_back #define fs first #define sc second template using V = vector; template using VV = vector>; template void chmax(T& x, U y){if(x void chmin(T& x, U y){if(y void mkuni(V& v){sort(all(v));v.erase(unique(all(v)),v.end());} template int lwb(const V& v, const T& a){return lower_bound(all(v),a) - v.begin();} template ostream& operator<<(ostream& o,const pair &p){ return o<<"("< ostream& operator<<(ostream& o,const vector &vc){ o<<"{"; for(const T& v:vc) o< struct ModInt{ using uint = unsigned int; using ll = long long; using ull = unsigned long long; constexpr static uint mod = mod_; uint v; ModInt():v(0){} ModInt(ll _v):v(normS(_v%mod+mod)){} explicit operator bool() const {return v!=0;} static uint normS(const uint &x){return (x [0 , mod-1] static ModInt make(const uint &x){ModInt m; m.v=x; return m;} ModInt operator+(const ModInt& b) const { return make(normS(v+b.v));} ModInt operator-(const ModInt& b) const { return make(normS(v+mod-b.v));} ModInt operator-() const { return make(normS(mod-v)); } ModInt operator*(const ModInt& b) const { return make((ull)v*b.v%mod);} ModInt operator/(const ModInt& b) const { return *this*b.inv();} ModInt& operator+=(const ModInt& b){ return *this=*this+b;} ModInt& operator-=(const ModInt& b){ return *this=*this-b;} ModInt& operator*=(const ModInt& b){ return *this=*this*b;} ModInt& operator/=(const ModInt& b){ return *this=*this/b;} ModInt& operator++(int){ return *this=*this+1;} ModInt& operator--(int){ return *this=*this-1;} ModInt pow(ll p) const { if(p<0) return inv().pow(-p); ModInt a = 1; ModInt x = *this; while(p){ if(p&1) a *= x; x *= x; p >>= 1; } return a; } ModInt inv() const { // should be prime return pow(mod-2); } // ll extgcd(ll a,ll b,ll &x,ll &y) const{ // ll p[]={a,1,0},q[]={b,0,1}; // while(*q){ // ll t=*p/ *q; // rep(i,3) swap(p[i]-=t*q[i],q[i]); // } // if(p[0]<0) rep(i,3) p[i]=-p[i]; // x=p[1],y=p[2]; // return p[0]; // } // ModInt inv() const { // ll x,y; // extgcd(v,mod,x,y); // return make(normS(x+mod)); // } bool operator==(const ModInt& b) const { return v==b.v;} bool operator!=(const ModInt& b) const { return v!=b.v;} bool operator<(const ModInt& b) const { return v>(istream &o,ModInt& x){ ll tmp; o>>tmp; x=ModInt(tmp); return o; } friend ostream& operator<<(ostream &o,const ModInt& x){ return o<; //using mint = ModInt<1000000007>; V fact,ifact,invs; mint Choose(int a,int b){ if(b<0 || a=0;i--) ifact[i] = ifact[i+1] * (i+1); rep1(i,N-1) invs[i] = fact[i-1] * ifact[i]; } int bsr(int x) { return 31 - __builtin_clz(x); } void ntt(bool type, V& c) { const mint G = 3; //primitive root int N = int(c.size()); int s = bsr(N); assert(1 << s == N); V a = c, b(N); rep1(i,s){ int W = 1 << (s - i); mint base = G.pow((mint::mod - 1)>>i); if(type) base = base.inv(); mint now = 1; for(int y = 0; y < N / 2; y += W) { for (int x = 0; x < W; x++) { auto l = a[y << 1 | x]; auto r = now * a[y << 1 | x | W]; b[y | x] = l + r; b[y | x | N >> 1] = l - r; } now *= base; } swap(a, b); } c = a; } V multiply_ntt(const V& a, const V& b) { int A = int(a.size()), B = int(b.size()); if (!A || !B) return {}; int lg = 0; while ((1 << lg) < A + B - 1) lg++; int N = 1 << lg; V ac(N), bc(N); for (int i = 0; i < A; i++) ac[i] = a[i]; for (int i = 0; i < B; i++) bc[i] = b[i]; ntt(false, ac); ntt(false, bc); for (int i = 0; i < N; i++) { ac[i] *= bc[i]; } ntt(true, ac); V c(A + B - 1); mint iN = mint(N).inv(); for (int i = 0; i < A + B - 1; i++) { c[i] = ac[i] * iN; } return c; } int main(){ cin.tie(0); ios::sync_with_stdio(false); //DON'T USE scanf/printf/puts !! cout << fixed << setprecision(20); InitFact(1000000); int N; cin >> N; string s; cin >> s; V f(N),g(N); rep(i,N){ if(s[i] == 'n') f[i] = 1; if(s[i] == 'i') g[N-1-i] = 1; } auto h = multiply_ntt(f,g); { V f(N-1); rep(i,N-1) f[i] = h[i+N]; show(f); rep(i,N-1) f[i] *= fact[i]; V g(N-1); rep(i,N-1) g[i] = ifact[N-1-i-1]; auto h = multiply_ntt(f,g); V res(N-1); rep(i,N-1) res[i] = h[N-2+i] * ifact[i]; ll ans = 0; for(auto v: res) ans ^= v.v; cout << ans << endl; } }