// @snippet<sh19910711/contest:headers.cpp>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <vector>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <algorithm>
#include <numeric>
#include <limits>
#include <complex>
#include <functional>
#include <iterator>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>

// @snippet<sh19910711/contest:solution/interface.cpp>
namespace solution {
    class ISolution {
    public:
        virtual void init() {};
        virtual bool input() { return false; };
        virtual void output() {};
        virtual int run() = 0;
    };
}

class BigInteger {
public:
    char *digits;
    int size;
    int capacity;
    int sign;

    BigInteger( int n, int cap ) {
        cap = std::max( cap, (int)sizeof(n) * 8 );
        capacity = cap;
        sign = sig(n);
        n *= sign;
        digits = new char[cap];
        memset( digits, 0, cap );
        for ( size = 0; n; ++ size ) {
            digits[size] = n % 10;
            n /= 10;
        }
    }

    BigInteger( int n ) {
        capacity = 1024;
        sign = sig(n);
        n *= sign;
        digits = new char[capacity];
        memset( digits, 0, capacity );
        size = 0;
        while ( n ) {
            digits[size++] = n % 10;
            n /= 10;
        }
    }

    BigInteger() {
        capacity = 128;
        sign = 0;
        digits = new char[capacity];
        memset( digits, 0, capacity );
        size = 0;
    }

    BigInteger( std::string s ) {
        capacity = std::max( (int)s.size(), 16 );
        sign = 0;
        digits = new char[capacity];
        memset( digits, 0, capacity );
        std::istringstream in(s);
        in >> (*this);
    }

    BigInteger( const char s[] ) {
        capacity = std::max( (int)strlen(s), 16 );
        sign = 0;
        digits = new char[capacity];
        memset( digits, 0, capacity );

        std::istringstream in(s);
        in >> (*this);
    }

    BigInteger( const BigInteger& n ) {
        capacity = n.capacity;
        sign = n.sign;
        size = n.size;
        digits = new char[capacity];
        memcpy( digits, n.digits, capacity );
    }

    static bool isDigit( int c ) {
        return ( c >= (int)'0' && c <= (int)'9' );
    }

    friend std::istream& operator >>( std::istream& in, BigInteger& n ) {
        n.size = 0;
        n.sign = 1;
        int sign = 1;
        int c;
        while ( ( c = in.peek() ) >= 0 &&
             ( c == ' ' || c == '\t' || c == '\r' || c == '\n' ) )
            in.get();
        if ( c < 0 || ( c != (int)'-' && ! isDigit(c) ) ) {
            in >> c;
            return in;      
        }
        if ( c == (int)'-' ) {
            sign = -1;
            in.get();
        }

        while ( ( c = in.peek() ) >= 0 && isDigit(c) ) {
            in.get();
            n *= 10;
            n += ( c - (int)'0' );
        }
        n.sign = sign;
        n.normalize();
        return in;
    }

    friend std::ostream& operator <<( std::ostream& out, BigInteger n ) {
        return out << n.toString();
    }

    const BigInteger& operator =( const BigInteger& n ) {
        if ( &n != this ) {
            if ( capacity < n.size ) {
                capacity = n.capacity;
                delete[] digits;
                digits = new char[capacity];
            }
            sign = n.sign;
            size = n.size;
            memcpy( digits, n.digits, size );
            memset( digits + size, 0, capacity - size );
        }
        return *this;
    }

    const BigInteger& operator =( int n ) {
        sign = sig(n);
        n *= sign;
        for ( size = 0; n; ++ size ) {
            digits[size] = n % 10;
            n /= 10;
        }
        return *this;
    }

    ~BigInteger() {
        delete[] digits;
    }

    void normalize() {
        while ( size && ! digits[size-1] )
            size --;
        if ( ! size )
            sign = 0;
    }

    int toInt() {
        int result = 0;
        for ( int i = size - 1; i >= 0; -- i ) {
            result *= 10;
            result += digits[i];
            if ( result < 0 )
                return sign * 0x7FFFFFFF;
        }
        return sign * result;
    }

    std::string toString() {
        std::string s = ( sign >= 0 ? "" : "-" );
        for ( int i = size - 1; i >= 0; -- i ) {
            s += ( digits[i] + '0' );
        }
        if ( size == 0 )
            s += '0';
        return s;
    }

    int sig( int n ) {
        return ( n > 0 ? 1 : ( n == 0 ? 0 : -1 ) );
    }

    void grow() {
        char* olddigits = digits;
        int oldCap = capacity;
        capacity *= 2;
        digits = new char[capacity];
        memcpy( digits, olddigits, oldCap );
        memset( digits + oldCap, 0, oldCap );
        delete [] olddigits;
    }

    BigInteger operator++() {
        operator +=(1);
        return *this;
    }

    BigInteger operator ++( int ) {
        return operator++();
    }

    BigInteger operator --() {
        operator -=(1);
        return *this;
    }

    BigInteger operator --( int ) {
        return operator--();
    }

    BigInteger operator -() {
        BigInteger result(*this);
        result.sign *= -1;
        return result;
    }

    BigInteger operator +( int n ) {
        BigInteger result(*this);
        result += n;
        return result;
    }

    BigInteger operator +( BigInteger n ) {
        BigInteger result(*this);
        result += n;
        return result;
    }
    
    BigInteger& operator +=( int n ) {
        if ( size == capacity )
            grow();

        int nsign = sig(n);
        if ( ! nsign )
            return *this;
        if ( ! sign )
            sign = nsign;
        if ( sign == nsign ) {
            n *= nsign;
            int carry = 0;
            int i;
            for ( i = 0; n || carry; ++ i ) {
                int dig = n % 10;
                int newdig = digits[i] + dig + carry;
                digits[i] = newdig % 10;
                carry = newdig / 10;
                n /= 10;
            }
            size = std::max( i, size );
        } else {
            operator -=( -n );
        }
        return *this;
    }

    BigInteger& operator +=( BigInteger n ) {
        int maxS = std::max( size, n.size ) + 1;
        while ( maxS >= capacity )
            grow();

        if ( ! n.sign )
            return *this;
        if ( ! sign )
            sign = n.sign;
        if ( sign == n.sign ) {
            int carry = 0;
            int i;
            for ( i = 0; i < maxS - 1 || carry; ++ i ) {
                int newdig = carry;
                if ( i < size )
                    newdig += digits[i];
                if ( i < n.size )
                    newdig += n.digits[i];
                digits[i] = newdig % 10;
                carry = newdig / 10;
            }
            size = std::max( i, size );
        } else {
            n.sign *= -1;
            operator-=(n);
            n.sign *= -1;
        }
        return *this;
    }

    BigInteger operator-( int n ) {
        BigInteger result(*this);
        result -= n;
        return result;
    }

    BigInteger operator-( BigInteger n ) {
        BigInteger result(*this);
        result -= n;
        return result;
    }

    BigInteger operator-=( int n ) {
        if ( size == capacity )
            grow();
        int nsign = sig(n);
        if ( ! nsign )
            return *this;
        if ( ! sign )
            sign = 1;
        if ( sign == nsign ) {
            BigInteger bin = n;
            if ( ( sign >= 0 && *this < bin ) || ( sign < 0 && *this > bin ) ) {
                operator=( toInt() - n );
                return *this;
            }

            n *= nsign;
            int carry = 0;
            int i;
            for ( i = 0; n || carry; ++ i ) {
                int dig = n % 10;
                int newdig = digits[i] - dig + carry;
                if ( newdig < 0 )
                    newdig += 10, carry = -1;
                else
                    carry = 0;
                digits[i] = newdig;
                n /= 10;
            }
            normalize();
        } else {
            operator+=(-n);
        }
        return *this;
    }

    BigInteger operator-=( BigInteger n ) {
        int maxS = std::max( size, n.size ) + 1;
        while ( maxS >= capacity )
            grow();

        if ( ! n.sign )
            return *this;
        if ( ! sign )
            sign = 1;
        if ( sign == n.sign ) {
            if ( ( sign >= 0 && *this < n ) || ( sign < 0 && *this > n ) ) {
                BigInteger tmp = n;
                tmp -= *this;
                *this = tmp;
                sign = -sign;
                return *this;
            }

            int carry = 0;
            int i;
            for ( i = 0; i < maxS - 1; ++ i ) {
                int newdig = carry;
                if ( i < size )
                    newdig += digits[i];
                if ( i < n.size )
                    newdig -= n.digits[i];
                if ( newdig < 0 )
                    newdig += 10, carry = -1;
                else
                    carry = 0;
                digits[i] = newdig;
            }
            if ( carry ) {
                if ( i )
                    digits[0] = 10 - digits[0];
                size = ( i ? 1 : 0 );
                for ( int j = 1; j < i; ++ j ) {
                    digits[j] = 9 - digits[j];
                    if ( digits[i] )
                        size = j + 1;
                }
                sign *= -1;
            }
            normalize();
        } else {
            n.sign *= -1;
            operator +=(n);
            n.sign *= -1;
        }
        return *this;
    }

    BigInteger operator*( int n ) {
        BigInteger result( 0, size + (int)sizeof(n) * 8 );
        int nsign = sig(n);
        n *= nsign;
        result.sign = sign * nsign;
        if ( ! result.sign )
            return result;

        int i, j;
        for ( i = 0; n; ++ i ) {
            int dig = n % 10;
            if ( dig ) {
                int carry = 0;
                for ( j = 0; j < size || carry; ++ j ) {
                    int newDig = result.digits[i+j] + ( j < size ? dig * digits[j] : 0 ) + carry;
                    result.digits[i+j] = newDig % 10;
                    carry = newDig / 10;
                }
            }
            n /= 10;
        }

        result.size = i + j - 1;
        return result;
    }

    BigInteger operator*( BigInteger n ) {
        BigInteger result( 0, size + n.size );
        result.sign = sign * n.sign;
        if ( ! result.sign )
            return result;

        int i, j;
        for ( i = 0; i < n.size; ++ i ) {
            if ( n.digits[i] ) {
                int carry = 0;
                for ( j = 0; j < size || carry; ++ j ) {
                    int newDig =
                        result.digits[i+j] +
                        ( j < size ? n.digits[i] * digits[j] : 0 ) +
                        carry;
                    result.digits[i+j] = newDig % 10;
                    carry = newDig / 10;
                }
            }
        }
        result.size = i + j - 1;
        return result;
    }

    void operator *=( int n ) {
        operator=( operator*( n ) );
    }

    void operator *=( BigInteger n ) {
        operator=( operator*( n ) );
    }

    BigInteger operator/( int n ) {
        if ( ! n )
            n /= n;
        BigInteger result(*this);
        result /= n;
        return result;
    }

    BigInteger operator/( BigInteger n ) {
        if ( ! n )
            n.size /= n.size;

        BigInteger result(*this);
        result /= n;
        return result;
    }

    void operator/=( int n ) {
        divide(n);
    }

    void operator/=( BigInteger n ) {
        divide(n);
    }

    BigInteger operator%( int n ) {
        BigInteger tmp(*this);
        return tmp.divide(n);
    }

    void operator%=( int n ) {
        operator=(divide(n));
    }

    int divide( int n ) {
        if ( ! n )
            n /= n;

        int nsign = sig(n);
        n *= nsign;
        if ( ! sign )
            return 0;
        sign *= nsign;

        int tmp = 0;
        for ( int i = size - 1; i >= 0; -- i ) {
            tmp *= 10;
            tmp += digits[i];
            digits[i] = tmp / n;
            tmp -= digits[i] * n;
        }
        normalize();
        return tmp;
    }

    BigInteger divide( BigInteger n ) {
        if ( ! n )
            n.size /= n.size;

        if ( ! sign )
            return 0;
        sign *= n.sign;

        int oldSign = n.sign;
        n.sign = 1;

        BigInteger tmp( 0, size );
        for ( int i = size - 1; i >= 0; -- i ) {
            tmp *= 10;
            tmp += digits[i];
            digits[i] = 0;
            while ( tmp >= n ) {
                tmp -= n;
                digits[i] ++;
            }
        }
        normalize();

        n.sign = oldSign;
        return tmp;
    }

    BigInteger operator <<( int n ) {
        BigInteger result(*this);
        result <<= n;
        return result;
    }

    void operator <<=( int n ) {
        if ( n < 0 ) {
            operator >>=( -n );
        } else if ( n > 0 ) {
            BigInteger mult( 1, 4 * n );
            for ( int i = ( 1 << 30 ); i; i >>= 1 ) {
                mult *= mult;
                if ( n & i )
                    mult *= 2;
            }
            operator*=(mult);
        }
    }

    BigInteger operator >>( int n ) {
        BigInteger result(*this);
        result >>= n;
        return result;
    }

    void operator >>=( int n ) {
        if ( n < 0 ) {
            operator<<=(-n);
        } else if ( n > 0 ) {
            BigInteger mult( 1, 4 * n );
            for ( int i = ( 1 << 30 ); i; i >>= 1 ) {
                mult *= mult;
                if ( n & i )
                    mult *= 2;
            }
            operator /=(mult);
        }
    }

    bool operator!() {
        return !size;
    }
    operator bool() {
        return size;
    }
    operator std::string() {
        return toString();
    }

    bool operator <( BigInteger n ) {
        return ( compare(n) < 0 );
    }

    bool operator >( BigInteger n ) {
        return ( compare(n) > 0 );
    }

    bool operator ==( BigInteger n ) {
        return ( compare(n) == 0 );
    }

    bool operator <=( BigInteger n ) {
        return ( compare(n) <= 0 );
    }

    bool operator >=( BigInteger n ) {
        return ( compare(n) >= 0 );
    }

    bool operator <( int n ) {
        return ( compare(BigInteger(n)) < 0 );
    }

    bool operator >( int n ) {
        return ( compare(BigInteger(n)) > 0 );
    }

    bool operator ==( int n ) {
        return ( compare(BigInteger(n)) == 0 );
    }

    bool operator <=( int n ) {
        return ( compare(BigInteger(n)) <= 0 );
    }

    bool operator >=( int n ) {
        return ( compare(BigInteger(n)) >= 0 );
    }

    int compare( BigInteger n ) {
        if ( sign < n.sign )
            return -1;
        if ( sign > n.sign )
            return 1;
        if ( size < n.size )
            return -sign;
        if ( size > n.size )
            return sign;
        for ( int i = size - 1; i >= 0; -- i ) {
            if ( digits[i] < n.digits[i] )
                return -sign;
            else if ( digits[i] > n.digits[i] )
                return sign;
        }
        return 0;
    }
};

// @snippet<sh19910711/contest:solution/multi_tests.cpp>
namespace solution {
    using namespace std;

    string a, b;

    class Solution: public ISolution {
    public:
        bool input() {
            return cin >> a >> b;
        }
        void solve() {
            BigInteger res = BigInteger(a) + BigInteger(b);
            if ( res.toString().size() > 80 )
                cout << "overflow" << endl;
            else
                cout << ( BigInteger(a) + BigInteger(b) ) << endl;
        }
        int run() {
            int tests;
            cin >> tests;
            for ( int i = 0; i < tests; ++ i ) {
                init();
                input();
                solve();
                output();
            }
            return 0;
        }
    };
    
}


// @snippet<sh19910711/contest:main.cpp>
int main() {
    return solution::Solution().run();
}

Measured memory_bytes: 1244