#include <stdio.h>
#include<string.h>
#include<ctype.h>
#include<stdlib.h>
int mark(int v[],int low,int high,int len);
int main()
{
  int t,i,j,len,val,flag,res,low,high;
  scanf("%d ",&t);
  while(t--)
  {
        char s[51];
        flag=0;
        scanf("%s ",s);
        int v[51]={0};
        len=strlen(s);
        for(i=0;i<len;i++)
        {
               if(s[i]>=49 && s[i]<=57)
               {
                val=s[i]-48;
                low=i-val;
                if(low<0)
                low=0;
                high=i+val;
                if(high>len-1)
                high=len-1;
                res=mark(v,low,high,len);
                if(res==0)
                {
                flag=1;
                break;
                }

               }
        }
        if(flag==0)
        printf("safe\n");
        else
        printf("unsafe\n");
  }
    return 0;

}
int mark(int v[],int low,int high,int len)
{
          int i;
          for(i=low;i<=high;i++)
          {
          if(v[i]==1)
          return 0;
          else
          v[i]=1;
          }
          return 1;
}