#include <cstdio> #include <algorithm> #include <cmath> using namespace std; int a[10000],m,n,k; int main() { scanf("%d%d",&n,&k); for (int i=0;i<n;++i) scanf("%d",&a[i]); sort(a,a+n); m=a[n-k]-a[k-1]; if (m<2) { printf("NO\n%d",m); return 0; } for (int i=2;i<=sqrt(m);++i) if (m%i==0) { printf("NO\n%d",m); return 0; } printf("YES\n%d",m); return 0; }
3
30
2015
30
2015