#include <stdio.h>

int main() {
	int a,b,c;
scanf("%d %d %d",&a,&b,&c);
if (a<b&&b<c){
	printf("yes");
}else if(a>b){
	printf("no");
} else if (b>c){
	printf("no");
} else if (a>c){
	printf("no");
} 
	return 0;
}