// @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;
    };
}

// @snippet<sh19910711/contest:math/big_integer.cpp>
namespace math {
    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( 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 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() {
            math::BigInteger res = math::BigInteger(a) + math::BigInteger(b);
            if ( res.toString().size() > 80 ) {
                cout << "overflow" << endl;
            } else {
                cout << res << 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