#include<bits/stdc++.h>
using namespace std;bool Mbe;
namespace MAOJUN{

const int N=1e5+5;
int n,m,p,s[N],a[N],b[N];

inline void slv(){
	scanf("%d%d%d",&n,&m,&p);
	for(int i=1;i<=n;i++)scanf("%d",&s[i]);
	for(int i=1;i<=p;i++){scanf("%d%d",&a[i],&b[i]);a[i]=((s[a[i]]-b[i])%m+m)%m;}
	sort(a+1,a+p+1);
	long long s=0,rs=1e18;
	for(int i=1;i<=p;i++)s+=a[i];
	for(int i=1;i<=p;i++)rs=min(rs,s-p*1ll*a[i]+m*(lower_bound(a+1,a+p+1,a[i])-a-1ll));
	printf("%lld\n",rs);
}
inline void main(){
	int T;scanf("%d",&T);while(T--)slv();
}

}bool Med;int main(){
#ifdef LOCAL
	freopen("data.in","r",stdin);
	freopen("data.out","w",stdout);
#endif
	MAOJUN::main();
#ifdef LOCAL
	fprintf(stderr,"%lfs\n",clock()/1000.);
	fprintf(stderr,"%lfMB\n",(&Mbe-&Med)/1024./1024);
#endif
	return 0;
}