#include<bits/stdc++.h>
using namespace std;
int a,f[100000];
int main(){
int n,m,i,j,l,ans=0;
cin>>l>>n>>m;
for(i=0;i<n;i++){
int t=a;
cin>>a;
f[i]=a-t;
}
int h=l;
int d=1;
while(d<=h){
int he=0,s=(h+d)/2;
for(i=0;i<n;i++){
if(f[i]<s){
he++;
}
}
if(he>m){
h=s-1;
}else{
ans=s;
d=s+1;
}
//cout<<d<<" "<<h<<endl;
}
cout<<ans;
return 0;
}
连样例都没过,有什么问题啊?