#include <stdio.h>
int main() {
int male_num, female_num, total = 0;
scanf("%d%d", &male_num, &female_num);
int males[male_num], females[female_num];
for(int i = 0; i < male_num; i++) {
scanf("%d", &males[i]);
}
for(int i = 0; i < female_num; i++) {
scanf("%d", &females[i]);
}
for(int i = 0; i < male_num; i++) {
for(int j = 0; j < female_num; j++) {
if(males[i] + females[j] > total) {
total = males[i] + females[j];
}
}
}
printf("%d\n", total);
return 0;
}