#include"cstdlib"#include"cstdio"#include"cstring"#include"cmath"#include"queue"#include"algorithm"#include"iostream"#include"map"#include"string"#define mod 1000000009#define ll long longusing namespace std;int main(){ int t; scanf("%d",&t); while(t--) { int n,m; int max=0; char v[123][77]; char x[77],ans[87]; scanf("%d",&n); int i,k,j; for(i=0;i<n;i++) scanf("%s",v[i]); for(i=0;v[0][i+2];i++) { for(j=2;v[0][i+j];j++) { for(k=0,m=0;k<=j;k++) x[m++]=v[0][i+k]; x[m]=' '; for(k=1;k<n;k++) if(strstr(v[k],x)==NULL) break; if(k==n&&j>=max) { if(j==max) { if(strcmp(x,ans)<0) strcpy(ans,x); } else strcpy(ans,x); max=j; } } } if(!max) printf("no significant commonalitiesn"); else printf("%sn",ans); }}
