#include <iostream>
#define ZERO 0
#define ZERO_BIT 0
#define ONE_BIT 1
#define WITHIN_RANGE 0
#define OVER_RANGE 1
using namespace std;
//错误1，忘记移位运算导致越界段错误。
//错误2，输出值不正确，应7实4。是因为使用numberCount没有另存副本。
//错误3，应7实际7，经过手算无误，在于原理理解有误。容斥原理误用了双生对偶定理。
//错误4，没有超范围判断，超范围不仅要上限不超，还要下限0不超不溢出变负数。
//错误5，注意中断标志位的效力范围，当标志为否定时，不要进行答案指标的运算。
const int N = 1e9 + 10;
const int M = 16 + 10;

int numberCount, primeCount;
int rankToPrime[M];

void declaration(){
    scanf("%d%d", &numberCount, &primeCount);
    for (int primeRank = 1; primeRank <= primeCount; primeRank ++){
        int prime;
        scanf("%d", &prime);
        rankToPrime[primeRank] = prime;
    }
}

int theorem(){
    int result = 0;
    for (int mask = 1; mask < (1 << primeCount); mask++){
        int overRangeFlag = WITHIN_RANGE;
        int countOneBit = 0;
        int bitRank = 1;
        long long primeAccumulation = 1;
        for (int maskToOperate = mask; maskToOperate != ZERO && overRangeFlag == WITHIN_RANGE; maskToOperate >>= 1, bitRank ++){
            if ((maskToOperate & 1) == ONE_BIT){
                if (primeAccumulation * rankToPrime[bitRank] <= numberCount && primeAccumulation * rankToPrime[bitRank] > 0){
                    primeAccumulation *= rankToPrime[bitRank];
                    countOneBit ++;
                }
                else{
                    overRangeFlag = OVER_RANGE;
                }
            }
        }
        if(overRangeFlag == WITHIN_RANGE){
            if(countOneBit % 2 ==ZERO) result -= numberCount / primeAccumulation;
            else result += numberCount / primeAccumulation;
        }
    }
    return result;
}

void outputResult(int result){
    printf("%d", result);
}

int main(){
    declaration();
    int result = theorem();
    outputResult(result);
    return 0;
}