#include <bits/stdc++.h>   using namespace std;   void readi(int &x) {     int v = 0, f = 1;     char c = getchar();     while (!isdigit(c) && c !=  - ) c = getchar();     if (c ==  - )       f = -1;     else       v = v * 10 + c -  0 ;     while (isdigit(c = getchar())) v = v * 10 + c -  0 ;     x = v * f;   }   void readll(long long &x) {     long long v = 0ll, f = 1ll;     char c = getchar();     while (!isdigit(c) && c !=  - ) c = getchar();     if (c ==  - )       f = -1;     else       v = v * 10 + c -  0 ;     while (isdigit(c = getchar())) v = v * 10 + c -  0 ;     x = v * f;   }   void readc(char &x) {     char c;     while ((c = getchar()) ==    )       ;     x = c;   }   void writes(string s) { puts(s.c_str()); }   void writeln() { writes(  ); }   void writei(int x) {     if (!x) putchar( 0 );     char a[25];     int top = 0;     while (x) {       a[++top] = (x % 10) +  0 ;       x /= 10;     }     while (top) {       putchar(a[top]);       top--;     }   }   void writell(long long x) {     if (!x) putchar( 0 );     char a[25];     int top = 0;     while (x) {       a[++top] = (x % 10) +  0 ;       x /= 10;     }     while (top) {       putchar(a[top]);       top--;     }   }   inline long long inc(int &x) { return ++x; }   inline long long inc(long long &x) { return ++x; }   inline long long inc(int &x, long long y) { return x += y; }   inline long long inc(long long &x, long long y) { return x += y; }   inline double inc(double &x, double y) { return x += y; }   inline long long dec(int &x) { return --x; }   inline long long dec(long long &x) { return --x; }   inline long long dec(int &x, long long y) { return x -= y; }   inline long long dec(long long &x, long long y) { return x -= y; }   inline double dec(double &x, double y) { return x -= y; }   inline long long mul(int &x) { return x = ((long long)x) * x; }   inline long long mul(long long &x) { return x = x * x; }   inline long long mul(int &x, long long y) { return x *= y; }   inline long long mul(long long &x, long long y) { return x *= y; }   inline double mul(double &x, double y) { return x *= y; }   inline long long divi(int &x) { return x = sqrt(x); }   inline long long divi(long long &x) { return x = sqrt(x); }   inline long long divi(int &x, long long y) { return x /= y; }   inline long long divi(long long &x, long long y) { return x /= y; }   inline double divi(double &x, double y) { return x /= y; }   inline long long mod(int &x, long long y) { return x %= y; }   inline long long mod(long long &x, long long y) { return x %= y; }   long long n, m, i, j, ans = 0;   string s;   int main() {     cin >> n >> s;     if (n == 1) {       if (s ==  ? ) {         cout <<  Yes ;         return 0;       } else {         cout <<  No ;         return 0;       };     }     s =     + s +    ;     for (i = 1; i + 1 < s.size(); i++) {       if (s[i] !=  ?  && s[i] == s[i - 1]) {         cout <<  No ;         return 0;       };     }     s[0] = s[2];     s[s.size() - 1] = s[s.size() - 3];     for (i = 1; i + 1 < s.size(); i++) {       if (s[i] ==  ? ) {         if (s[i - 1] != s[i + 1] && s[i - 1] !=  ?  && s[i + 1] !=  ? )           ans++;         else {           cout <<  Yes ;           return 0;         };       }     }     {       cout <<  No ;       return 0;     };     return 0;   }