#define _CRT_SECURE_NO_WARNINGS #include #include #include #include #include #include #include #include #include #include #include #define rep(i,j,k) for(int i=(int)j;i<(int)k;i++) #define repp(i,j,k) for(int i=j;i>=k;i--) #define llrep(i,j,k) for(long long int i=j;i<(long long int)k;i++) #define Sort(x) sort(x.begin(),x.end()); #define vi vector #define vvi vector> #define ll long long int mod=1e9+7; const int INF = 1e9; using namespace std; int main(void) { int n; string s; cin >> n >> s; vector v(n); stack st; for (int i = 0; i