# include <cstdio>

typedef long long ll ;
const char FIN[] = "grupuri.in", FOU[] = "grupuri.out" ;
const int MAX = 100005;

ll SUM[MAX] ;
int V[MAX] ;
int N, K ;

ll solve ( int N, int K ) {
    if ( V[N] > SUM[N] / K ) {
        return solve ( N - 1, K - 1 ) ;
    } else {
        return SUM[N] / K ;
    }
}

int main () {
    freopen ( FIN, "r", stdin ) ;
    freopen ( FOU, "w", stdout ) ;

    scanf ( "%d %d", &K, &N ) ;

    for ( int i = 1; i <= N; ++i ) {
        scanf ( "%d", &V[i] ) ;
        SUM[i] = SUM[i - 1] + V[i] ;
    }

    printf ( "%lld", solve ( N, K ) ) ;

    return 0;
}