#include <stdio.h>

int main(void){
    int i, j, M, N, A, temp;
    scanf("%d %d", &N, &M);
    int card[N+1];
    for(i=1;i<=N;i++){
        card[i] = i;
    }
    for(i=0;i<M;i++){
        scanf("%d" ,&A);
        if(A!=1){
            temp = card[A];
            for(j=A;j>1;j--){
                card[j] = card[j-1];
            }
            card[1] = temp;
        }
    }
    printf("%d\n", card[1]);
    return 0;
}