
int main()
{int max,min,a[20001]={0},n,x,y,j,i,sum=0;

	scanf("%d",&n);
	for(i=1;i<=n;i++){
		scanf("%d %d",&x,&y);
		if(i==1){min=2*x;max=2*y;}
		else{if(min>2*x)min=2*x;
			if(max<2*y)max=2*y;}
		for(j=2*x;j<=2*y;j++){a[j]=1;}}
	for(i=min;i<=max;i++){
		sum+=a[i];}
	if(sum==max-min+1){printf("%d %d",min/2,max/2);}
	else{printf("no");}
return 0;}