#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
int main(){
    int n;
    scanf("%d",&n);
    while(n--){
        char a[1000] = {0};
        char b[1000] = {0};
        scanf("%s%s",a,b);
        int len_a = strlen(a),len_b = strlen(b);
        char ans[1000] = {0};
        reverse(a,a+len_a);
        reverse(b,b+len_b);
        for(int i = 0; i < max(len_a,len_b); i++){
            if(ans[i] != 0){
                if(a[i] == 0 || b[i] == 0)
                    ans[i] += a[i] + b[i] - '0';
                else ans[i] += a[i] + b[i] - '0' - '0';
            }
            else if(a[i] == 0 || b[i] == 0) ans[i] += a[i] + b[i];
            else ans[i] += a[i] + b[i] - '0';
            if(ans[i] >= 58){
                ans[i+1]+='1';
                ans[i] -= 10;
            }
        }
        int len_ans = strlen(ans);
        reverse(ans,ans+len_ans);
        if(len_ans > 80){
            printf("overflow\n");
            continue;
        }
        for(int i = 0; ans[i] != 0; i++) printf("%c",ans[i]);
        printf("\n");
    }
    return 0;
}