#include<stdio.h>
#include<string.h>
int main(void){
   int n;
   scanf("%d",&n);
   while(n--){
      char a[1000],b[1000],c[1000];
      int j,len;

      for(j=0;j<81;j++){
         a[j]=0;
         b[j]=0;
         c[j]='0';
      }
      scanf("%s%s",a,b);
      len=strlen(a);
      if(len<strlen(b))
         len=strlen(b);
      if(len>80){
         printf("overflow\n");
         continue;
      }
      /*for(j=0;j<len+1;j++){
         c[j]='0';9999999999999999999999999999999999999999999999999999999999999999999999999999999
      }*/
      for(j=0;j<strlen(a);j++){
         c[j]=a[strlen(a)-j-1];
      }
      for(j=0;j<strlen(b);j++){
         c[j]+=b[strlen(b)-j-1]-'0';
      }
      for(j=0;j<len;j++){
         if(c[j]>=58){
            if(j==len-1){
               c[j+1]='0';
               len++;
            }
            c[j]-=10;
            c[j+1]+=1;
         };
      }
      if(len>80){
         printf("overflow\n");
         continue;
      }
      else{
         for(j=len-1;j>=0;j--){
            printf("%c",c[j]);
         }
         puts("");
      }
   }
   return 0;
}

//9999999999999999999999999999999999999999999999999999999999999999999999999999999