#include using namespace std; #define rep(i,a,b) for(LL i = a;i=b; i--) #define INF ((1LL<<62)-(1LL<<31)) #define ooki 9,223,372,036,854,775,807 #define tii -9,223,372,036,854,775,808 typedef long long LL; int main(){ string s; getline(cin,s); rep(i,0,s.size()){ if(i%2==0&&s[i]==' '||i%2==1&&s[i]!=' '){ cout<<"No";return 0; } // if(i%2==0&&s[i]!=' '){cout<<"No";return 0;} } cout<<"Yes"<