#include <bits/stdc++.h>
typedef long long ll;
#define InAHurry cin.tie(0)->sync_with_stdio(0);
using namespace std;
int main(){
    InAHurry;
  int t;
  cin>>t;
  while(t--) {
      int n;
      cin>>n;
      string a,b;
      cin>>a>>b;
      vector<int> va,vb;
      for(auto i=0;i<n;i++) {
          if(isdigit(a[i])) va.push_back(a[i]);
          if(isdigit(b[i])) vb.push_back(b[i]);
      }
      if( va == vb ) cout<<"yes\n";
      else
      cout<<"no\n";
  }
    return 0;
}