#include <cstdio>
#include <iostream>

using namespace std;

int main(void) {
	int sets;
	char input1[100], input2[100], out[100];
	int i1, i2, o, carry;
	int ic1, ic2;
	int i;

	cin >> sets;
	for(i=0;i<sets;i++) {
		scanf("%s", input1);
		for(i1=0;input1[i1] != '\0';i1++);
		if(i1 > 80) {
			printf("overflow\n");
		} else {
			scanf("%s", input2);
			for(i2=0;input2[i2] != '\0';i2++);
			if(i2 > 80) {
				printf("overflow\n");
			} else {
				i1--;i2--;o=0;carry=0;
				while(i1>=0 || i2>=0 || carry) {
					if(o > 80) { break; }
					if(i1>=0) { ic1 = input1[i1]-'0'; i1--; } else { ic1 = 0; }
					if(i2>=0) { ic2 = input2[i2]-'0'; i2--; } else { ic2 = 0; }
					if( ic1+ic2+carry < 10 ) { 
						out[o] = ic1+ic2+carry+'0';
						carry = 0;
					} else {
						out[o] = ic1+ic2+carry-10+'0';
						carry = 1;
					}
					o++;
				}
				if(o > 80) {
					printf("overflow\n");
				}
				else {
					for(o--;o>=0;o--) {
						printf("%c", out[o]);
					}
					printf("\n");
				}
			}
		}
	}

	return 0;
}