#include typedef long long ll; typedef long double ld; const int INF=1e9,MOD=1e9+7,ohara=1e6+10; const ll LINF=1e18; using namespace std; #define rep(i,n) for(int (i)=0;(i)<(int)(n);(i)++) #define rrep(i,a,b) for(int i=(a);i<(b);i++) #define rrrep(i,a,b) for(int i=(a);i>=(b);i--) #define all(v) (v).begin(), (v).end() #define Size(n) (n).size() #define Cout(x) cout<<(x)< #define m_p make_pair #define V vector #define U_MAP unordered_map #define pq priority_queue #define rpq priority_queue,greater> #define p_b push_back ll n,cnt,ans,a[ohara],b,c,d,tmp,tmpp,m,h,w,x[ohara],y,sum,pos,k; ld doua; int dy[]={1,0,-1,0}; int dx[]={0,1,0,-1}; //int dy[]={-1,0,1,-1,1,-1,0,1}; //int dx[]={-1,-1,-1,0,0,1,1,1}; string alph("abcdefghijklmnopqrstuvwxyz"),s; bool fl; struct edge{int to,cost;}; //-------------------------↓↓↓↓↓↓------------------------ //------ 自分を天才だと信じる ------ int main(void){ cin.tie(0); cout.tie(0); ios::sync_with_stdio(false); cin>>n>>k; rep(i,n)cin>>x[i]; rep(i,n)cin>>a[i]; k--; //負の方向に ll lim=x[k]-a[k]; ans=1; rrrep(i,k-1,0){ if(x[i]lim)break; lim=max(lim,x[i]+a[i]); ans++; } Cout(ans); return 0; }