c(const void*a,const void*b){return*(int*)a-*(int*)b;}i,s,a[1<<17];main(n){for(scanf("%d",&n);~scanf("%d",++i+a););qsort(a+1,n,4,c);for(;n--;a[n]-a[n+1]&&a[n+1]-a[n+2]&&s++);s=!printf("%d",s);}