# include<iostream> # include<cstring> using namespace std; int main(){ int n,i,j,ss=0,m=-1; cin>>n; int a[n]; for (i=1;i<=n;i++) cin>>a[i]; for (i=1;i<=n;i++){ ss=0; for (j=i+1;j<=n;j++){ if (a[i]-a[j]<=2){ ss++; if (ss>m) m=ss; } } } cout<<m+1; return 0; }