#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
typedef pair<int, int> pint;
#define REP(i, n) for(int i = 0; i < (int)(n); i++)
#define IREP(i, n) for(int i = (int)(n) - 1; i >= 0; i--)
#define ALL(x) (x).begin(), (x).end()
#define MOD 1000000007
#define IMAX INT_MAX
#define IMIN INT_MIN
#define LMAX LLONG_MAX
#define LMIN LLONG_MIN
template<typename T> inline void chmin(T &a, T b){ if(a > b) a = b; }
template<typename T> inline void chmax(T &a, T b){ if(a < b) a = b; }
template<typename T> inline void xch(T &a, T &b){ T w = a; a = b; b = w; }


int main() {
    int N;
    cin >> N;
    REP(notc, N){
        string s1, s2;
        cin >> s1;
        cin >> s2;
        int len1 = s1.length() - 1, len2 = s2.length() - 1;
        int n[90];
        int length = 0;
        REP(i, 90){
            n[i] = 0;
        }
        REP(i, 82){
            int a = (len1 - i >= 0)?s1[len1 - i] - '0':0;
            int b = (len2 - i >= 0)?s2[len2 - i] - '0':0;
            n[i] += a + b;
            n[i + 1] += n[i] / 10;
            n[i] %= 10;
            if(n[i] != 0) length = i + 1;
        }
        if(length >= 81){
            cout << "overflow" << endl;
        }
        else if(length == 0){
            cout << 0 << endl;
        }
        else{
            IREP(i, length){
            cout << n[i];
            }
            cout << endl;
        }
        
    }
    return 0;
}

