#include <stdio.h>

int main(void) {
    int n = 0;
    scanf("%d", &n);
    int x[3];
    int y[3];
    for (int i = 0; i < 3; i++) {
        scanf("%d %d", &x[i], &y[i]);
    }
    //输出数列x和y的全部元素；
    for (int i = 0; i < 3; i++) {
        printf("x=%d y=%d\n", x[i], y[i]);
    }

    int temp = 99999999;
    

        for (int i = 0; i<3 ; i++) {
                  int v = n;
                  int m = 0;
            while (v > 0) {
                v -= x[i];
                m++;
                printf("temp=%d m=%d y[i]=%d\n", temp, m,y[i]);
            }
            if ((y[i] * m) < temp&&m!=0) {
                    temp = y[i] * m;
                }

        }
    printf("%d\n", temp);
    return 0;
}