#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;
}