#include<cstdio>

 #include<cstring>

 #include<string>

 #include<cmath>

 #include<iostream>

 #include<algorithm>

 #include<map>

 #include<set>

 #include<queue>

 #include<vector>

 using namespace std;

 typedef long long ll;

 typedef unsigned int uint;

 typedef unsigned long long ull;

 typedef pair<int,int> PII;

 typedef vector<int> VI;

 #define fi first

 #define se second

 #define MP make_pair

 #define N   1100000

 #define MOD 1000000007

 #define eps 1e-8

 #define pi acos(-1)

 int main()

 {

     ll n,m,k,l;

     scanf("%lld%lld%lld%lld",&n,&m,&k,&l);

     if(n<m||l>n-k) printf("-1\n");

      else

      {

          ll ans=(k+l)/m;

          if(ans*m<k+l) ans++;

          if(ans*m<=n) printf("%lld\n",ans);

           else printf("-1\n");    //7 4 1 6 ANS=-1

      }

     return ;

 }