#include<stdio.h>
#include<string.h>
#define N 2100
int degree[N];
int pre[N];//很长时间没写欧拉回路了忘了判断他是否联通了
int find(int x) {
if(x!=pre[x])
pre[x]=find(pre[x]);
return pre[x];
}
int main() {
int t,n,m,i,ans,a,b,aa,bb;
scanf("%d",&t);
while(t--) {
scanf("%d%d",&n,&m);
memset(degree,0,sizeof(degree));
for(i=1;i<=n;i++)
pre[i]=i;
while(m--) {
scanf("%d%d",&a,&b);
degree[a]++;
degree[b]++;
aa=find(a);
bb=find(b);
if(aa!=bb)
pre[aa]=bb;
}
ans=0;
for(i=1;i<=n;i++)
if(pre[i]==i)
ans++;
if(ans>1) {
printf("No\n");
continue;
}
ans=0;
for(i=1;i<=n;i++)
if(degree[i]%2==1)
ans++;
if(ans==2||ans==0)
printf("Yes\n");
else
printf("No\n");
}
return 0;
}