#include <stdio.h>
#include <string.h>

int main(void)
{
	int n, i, j, k, overflow, nonzero, a[1000] = {0}, b[1000] = {0}, sum[1000] = {0};
	char stra[1001], strb[1001];
	
	scanf("%d", &n);
	
	for (i = 0; i < n; i++){
		overflow = 0;
		nonzero = 0;
		
		scanf("%s", stra);
		scanf("%s", strb);
		
		k = 0;
		for (j = strlen(stra) - 1; j >= 0; j--){
			a[k] = stra[j] - '0';
			k++;
		}
		
		k = 0;
		for (j = strlen(strb) - 1; j >= 0; j--){
			b[k] = strb[j] - '0';
			k++;
		}
		
		for (j = 0; j < 100; j++){
			sum[j] += a[j] + b[j];
			
			if (j > 79 && sum[j] != 0){
				printf("overflow\n");
				overflow = 1;
				break;
			}
			
			if (sum[j] > 9){
				sum[j+1]++;
				sum[j] -= 10;
			}
		}
		
		if (overflow == 0){
			for (j = 79; j >= 0; j--){
				if (nonzero == 0 && sum[j] != 0){
					nonzero = 1;
				}
				
				if (nonzero == 1){
					printf("%d", sum[j]);
				}
			}
			puts("");
		}
	}
	
	return (0);
}