#include<bits/stdc++.h>
using namespace std;


void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i : x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}

#define fo(i, n) for(int i=0; i<n; i++)
#define Fo(i, k, n) for(int i=k; i<n; i++)
#define w(x)  int x; cin>>x; while(x--)
#define watch(x) cout << (#x) << " is " << (x) << "\n"
#define watch2(x,y) cout <<(#x)<<" is "<<(x)<<" and "<<(#y)<<" is "<<(y)<<"\n"
#define watch3(x,y,z) cout <<(#x)<<" is "<<(x)<<" and "<<(#y)<<" is "<<(y)<<" and "<<(#z)<<" is "<<(z)<<"\n"
#define watch4(x,y,z,q) cout <<(#x)<<" is "<<(x)<<" and "<<(#y)<<" is "<<(y)<<" and "<<(#z)<<" is "<<(z)<<" and "<<(#q)<<" is "<<(q)<<"\n"
#define MOD 1000000007
#define INF 1000000007;
#define F first
#define S second
#define pb(x) push_back(x);


#define ll  long long
#define all(c) (c).begin(),(c).end()
#define endl "\n"

typedef vector<int> vl;
typedef vector< vl > vvl;
typedef pair< int, int> pll;
typedef map< int, int> mll;


#ifndef ONLINE_JUDGE
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif





void c_p_c()
{
#ifndef ONLINE_JUDGE
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
#endif
}
void parray(int a[], int n) {
	for (int i = 0; i < n; i++) {
		cout << a[i] << " ";
	}
	cout << endl;
}
int disum(int n) {
	int sum = 0;

	while (n) {

		sum += n % 10;
		// sum++;
		n /= 10;





	}
	return sum;

}


#define maxa 1000000

int freq[maxa];



bool check(int mid,int n){
	bool f=false,s=false;
	int t=n+1;
	for (int i = 1; i < n+1; ++i)
	{
		/* code */
		if(freq[i]>=mid){
			f=true;
			t=freq[i];
			break;
		}
	}
	int c=0;
	for (int i = 1; i < n+1; ++i)
	{
		/* code */
		if(freq[i]>0){
			c++;
			if(freq[i]==t  and t-mid<=0){
				t=n+1;
				c--;
			}





		}
		if(c>=mid){
			s=true;
			break;
		}
	}




	return (f and s);
}







int main() {
	int i, n, m, k, c1 = 0, sum = 0;
	c_p_c();
	// w(t){

		cin>>n;
		
		string s[n];
		set<string> st;
		for (int i = 0; i < n; ++i)
		{
			/* code */
			cin>>s[i];
			st.insert(s[i]);
		}
		if(st.size()!=n)
			cout<<"No"<<endl;
		else{

			int pp=0;

			// int p=0;
			int len=s[0].size();
			char last = s[0][len-1];

			for (int i = 1; i < n; ++i)
			{
				/* code */
				int len2= s[i].size();
				char ch = s[i][0];
				// watch2(ch,last);
				if(last!=ch){
					pp=1;
					break;
				}

				last=s[i][len2-1];
			}

			if(!pp)
				cout<<"Yes"<<endl;
			else
				cout<<"No"<<endl;








		}









		
	return 0;


}


// 3
// 2
// 3
// 4
// 2
// 3
// 4
// 2
// 3

Measured memory_bytes: 3632