#define Z(C,D,P)for(l=1,h=N;l<h;l<h&&(C))for(;l<h&&v[l]P-v[h];D);R=!printf("%d ",R);
v['abc'],N,R,l;main(h){for(;~scanf("%d",v+N++););qsort(v+1,N-=2,4,"\x8b\7+\6\xc3");Z(R++|l++|h--,h--,>=)Z(R++|l++|h--,l++,<=)Z(v[l++]+v[h]||R++|h--,h--,>)}