#include <stdio.h>

void main() {
	int i, j, n, k, count = 0;
	scanf("%d",&n);
	int m[n];
	for (i=0;i<n;i++) {
		scanf("%*c%d", &m[i]);
	}
	for (i=0;i<n-1;i++){
		k = m[i];
		for (j=i+1;j<n;j++){
			if (m[j] < k)
				count++;
		}
	}
	printf("%d",count);
}