#include <stdio.h>

int main(void) {
	int n, a0, a1;
	int i, count = 0;
	scanf("%d", &n);
	scanf("%d", &a0);
	for(i = 1;i < n;i++){
		scanf("%d", &a1);
		if(a0 > a1)count++;
		a0 = a1;
	}
	printf("%d\n", count);
	
	return 0;
}