vijos 1002

#include<cstdio>
#include<cctype>
#include<algorithm>
using namespace std;
int read(){
    char c; while(!isdigit(c=getchar())); int x=c-‘0‘;
    while(isdigit(c=getchar())) x=x*10+c-‘0‘; return x;
}
int st[102],f[100001],dp[100001];
int main(){
    int l=read(),s=read(),t=read(),m=read();
    for(int i=1;i<=m;i+=1) st[i]=read();
    sort(st+1,st+m+1);
    if(s==t){
        int ans=0;
        for(int i=1;i<=m;i+=1)
            if(st[i]%s==0) ans++;
        printf("%d",ans);
        return 0;
    }
    int p=9%(t-s)? (9/(t-s)+1)*t:9/(t-s)*t;
    int j=0;
    for(int i=1;i<=m;i+=1) if(st[i]-st[i-1]>=p){j+=p; f[j]=1;} else j+=st[i]-st[i-1],f[j]=1;
    dp[0]=f[0];
    for(int i=1;i<=j+p;i+=1){
        dp[i]=2e9;
        for(int j=s;j<=t;j+=1)
            if(i-j>=0)
                dp[i]=min(dp[i-j]+f[i],dp[i]);
    }
    printf("%d",dp[j+p]);
    return 0;
}