// template version 1.12 using namespace std; #include #include // varibable settings #define infile "../test/sample-1.in" #define int long long //{{{ const int INF=1e18; const int MOD=1e9+7; //}}} // define basic macro {{{ #define _overload3(_1,_2,_3,name,...) name #define _rep(i,n) repi(i,0,n) #define repi(i,a,b) for(int i=(int)(a);i<(int)(b);++i) #define rep(...) _overload3(__VA_ARGS__,repi,_rep,)(__VA_ARGS__) #define _rrep(i,n) rrepi(i,0,n) #define rrepi(i,a,b) for(int i=(int)((b)-1);i>=(int)(a);--i) #define rrep(...) _overload3(__VA_ARGS__,rrepi,_rrep,)(__VA_ARGS__) #define each(i,a) for (auto&& i : a) #define all(x) (x).begin(),(x).end() #define sz(x) ((int)(x).size()) #define pb(a) push_back(a) #define mp(a, b) make_pair(a, b) #define uni(x) sort(all(x));x.erase(unique(all(x)),x.end()) #define ub upper_bound #define lb lower_bound #define posl(A, x) (lower_bound(all(A), x)-A.begin()) #define posu(A, x) (upper_bound(all(A),x)-A.begin()) template inline void chmax(T &a, const T &b) { if((a) < (b)) (a) = (b); } template inline void chmin(T &a, const T &b) { if((a) > (b)) (a) = (b); } typedef long long ll; typedef vector vi; typedef vector vvi; typedef long double ld; typedef pair pii; typedef tuple iii; template using PQ = priority_queue, greater>; struct Fast { Fast(){ std::cin.tie(0); ios::sync_with_stdio(false); } } fast; #if defined(PCM) || defined(LOCAL) #include "lib/dump.hpp" #else #define dump(...) 42 #define dump_1d(...) 42 #define dump_2d(...) 42 #endif //}}} int solve(){ int n,k;cin>>n>>k;k--; vi x(n),a(n); rep(i,n)cin>>x[i]; rep(i,n)cin>>a[i]; int ans=1; { int r=k; int l=k; int R = -INF; int L = INF; while(true){ bool flag=false; if (r0){ chmin(L, x[l]-a[l]); if (L<=x[l-1]){ dump(l-1); ans++; l--; flag=true; } } if (!flag) break; } } cout << ans << endl; return 0; } signed main() { //{{{ #ifdef INPUT_FROM_FILE std::ifstream in(infile); std::cin.rdbuf(in.rdbuf()); #endif solve(); return 0; } //}}}