#include<stdio.h>

int main(){
	char x[100], y[100], z[100];
	int n, xl, yl, zl;
	int i;

	scanf("%d",&n);
	for(i=0;i<n;i++){
		scanf("%s",x);
		scanf("%s",y);
		for(xl=0;x[xl]!='\0';xl++) x[xl]-='0';
		for(yl=0;y[yl]!='\0';yl++) y[yl]-='0';
		xl--;
		yl--;
		if(xl>80 || yl>80){
			printf("overflow\n");
			continue;
		}

		for(zl=0;zl<100;zl++) z[zl]=0;
		for(zl=0;xl>=0 || yl>=0;zl++){
			if(xl>=0) z[zl]+=x[xl--];
			if(yl>=0) z[zl]+=y[yl--];
			if(z[zl]>=10){
				z[zl]-=10;
				z[zl+1]++;
			}
		}

		for(zl=99;z[zl]==0;zl--){}
		if(zl>80){
			printf("overflow\n");
			continue;
		}
		for(xl=0;zl>=0;zl--) x[xl++]=(z[zl]+'0');
		x[xl] = '\0';
		printf("%s\n",x);
	}
	return 0;
}