#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
int main(void){
    int n;
    scanf("%d",&n);
    while(n--){
        int x[1000] = {0},y[1000] = {0},sum[1000] ={0};
        char a[1000] = {0},b[1000] = {0};
        scanf("%s%s",a,b);
        int c = max(strlen(a),strlen(b));
        int cnt1 = 1,cnt2 = 1;
        for(int i = 100;i>=0; i--){
            if(a[i] != '\0'){
                x[cnt1] = a[i]-'0';
                cnt1++;
            }
            if(b[i] != '\0'){
                y[cnt2] = b[i] - '0';
                cnt2++;
            }
        }
        for(int i = 1;i <= 100; i++){
            sum[i] += x[i] + y[i];
            if(sum[i] > 9){
                sum[i] -= 10;
                sum[i+1] = sum[i+1]++;
            }
        }
        int d = 0;
        if(sum[c+1] == 0)d = 1;
        cnt1 = 0;
        for(int i = c+1-d; i >= 0; i--){
            if(i==0 && sum[0]==0 && cnt1==81){
                goto overflow;
            }
            cnt1++;
        }
        for(int i = c+1-d; i >= 0; i--){
            if(i==0 && sum[0]==0)break;
            printf("%d",sum[i]);
        }
        printf("\n");
        continue;
        overflow:
        printf("overflow\n");
    }
    return 0;
}