#include<stdio.h>
#define MAX 1000000
int main(){
  float  N,M,A[i];
  scanf("%f\n",&N);
  scanf("%f\n",&M);
  for(i=1,i<M+1,i++){
    scanf("%f\n",&A[i]);
  }
  for(i=1,i<M+1,i++){
    homeworktime=A[i]+;
  }
  answer=N-homeworktime;
  printf("/d\n",answer);
  
  return 0
}
  