#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

#define rd_init() char*rp=({char*mmap();mmap(0l,1l<<25,1,2,0,0ll);})
#define rd_skip_line() while(*rp++!=10)

int main(){
	rd_init();
	rd_skip_line();
	for(int c;;){
		c=*rp++;
		if(c==10){
			write(1,"Yes",3);
			_exit(0);
		}else if(c=='?'){
			rp+=0x00008002>>(*rp&31)&1;
		}else if(c=='n'||c=='w'&&0x80008002>>(*rp++&31)&1){
		}else{
			write(1,"No",2);
			_exit(0);
		}
	}
}