#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

#define rd_init() char*rp=({char*mmap();mmap(0l,1l<<25,1,2,0,0ll);})
#define rd() ({int _v=0,_c;while(_c=*rp++-48,_c>=0)_v=_v*10+_c;_v;})
#define wt(v) ({ulong _z=v;do*--wp=_z%10+48;while(_z/=10);})
#define wt1(v) ({char wbuf[64],*wp=wbuf+sizeof wbuf;wt(v);write(1,wp,wbuf+sizeof wbuf-wp);})
#define rep(v,e) for(typeof(e) v=0;v<e;++v)
#define chmin(v,a) (v=v<=a?v:a)

typedef unsigned long ulong;

int c[200000];
struct{
	int a;
	int d;
}ad[200000];

int main(){
	rd_init();
	int n=rd();
	int m=rd();
	int k=rd();
	long z=1l<<62;
	rep(i,n){
		c[i]=rd()-1;
	}
	rep(j,m){
		ad[j].a=rd();
		chmin(z,ad[j].a);
		ad[j].d=k;
	}
	z*=k;
	rep(i,n){
		if(i>=k){
			ad[c[i-k]].d+=1;
		}
		ad[c[i]].d-=1;
		chmin(z,(long)ad[c[i]].d*ad[c[i]].a);
	}
	wt1(z);
	_exit(0);
}