#include<cstdlib>
#include<iostream>
#include<cstdio>
#include<cmath>
#include<set>
#include<cstring>
#include <algorithm>
#define inf 0x7fffffff
#define N 450000
#define MIN 1e-11
#define M 100
#define LL long long
using namespace std;
int n,k,h,t,m;
int a[N],b[N],low[M],high[M];
int main()
{
#ifndef ONLINE_JUDGE
freopen("ex.in","r",stdin);
#endif
scanf("%d",&t);
while(t--)
{
memset(a,0,sizeof(a));
memset(b,0,sizeof(b));
int v,minv=inf,temp;
scanf("%d%d",&v,&n);
v*=1000;
for(int i=0; i<n; ++i)
{
scanf("%d%d",&low[i],&high[i]);
temp=low[i]*low[i]/(high[i]-low[i]);
if(minv>temp)
minv=temp;
}
if(v>minv)
{
printf("0\n");
if(t)
printf("\n");
continue;
}
a[0]=1;
for(int i=0; i<n; i++)
for(int j=low[i]; j<=v; j++)
{
if(a[j-low[i]])
{
a[j]=1;
b[j]=max(b[j],b[j-low[i]]+high[i]);
}
}
int maxv=0;
for(int i=v; i>=0; i--)
if(b[i]>maxv)
{
maxv=b[i];
if(maxv>=v)
{
maxv=v;
break;
}
}
printf("%d\n",v-maxv);
if(t)
printf("\n");
}
return 0;
}