#include <cstdio>
#define N 33333
int n,a[N],s1[N],s2[N],ans=1<<30;
int main(){
    freopen("diningb.in","r",stdin);
    freopen("diningb.out","w",stdout);
    scanf("%d",&n);
    for(int i=1;i<=n;i++){
        scanf("%d",&a[i]);
        s1[i]=s1[i-1];s2[i]=s2[i-1];
        if (a[i]==1) ++s1[i];
        else ++s2[i];
    }
    for(int i=0;i<=n;i++) ans<?=s2[i]+s1[n]-s1[i];
    printf("%d\n",ans);
    return 0;
}