import sys

def status(red, green, time):
    if time < red:
        a = ['Red', red - time]
        return a
    else:
        i = 0
        j = 0
        while i < time:
            if j % 2 == 0:
                i += red
            else:
                i += green
            j += 1
        if j % 2 == 0:
            a = ['Green']
        else:
            a = ['Red', i - time]
        return a

def main():
    s = sys.stdin.read().strip().split()
    L = int(s[0])
    D = [int(s[i]) for i in range(len(s)) if i % 3 == 1]
    R = [int(s[i]) for i in range(len(s)) if i % 3 == 2]
    G = [int(s[i]) for i in range(1, len(s)) if i % 3 == 0]
    time = 0
    distance = 0
    j = 0
    while distance < L:
        if distance not in D:
            distance += 1
            time += 1
        else:
            if status(R[j], G[j], time)[0] == 'Green':
                distance += 1
                time += 1
            elif status(R[j], G[j], time)[0] == 'Red':
                time += status(R[j], G[j], time)[1]
                distance += 1
                time += 1
            j += 1
    print(time)

if __name__ == '__main__':
    main()