#include<iostream>
using namespace std;
int main()
{
    int k,n,a[1001],i,j=0,ans[1001]={0},sum;
    cin>>k>>n;
    for(i=0;i<n;i++)
    {cin>>a[i];}
    for(i=0;i<n;i++)
    {
    if((ans[i-1]+a[i])-k<=0){ans[i]=0;}
    else if((ans[i-1]+a[i])-k<=0 and ans[i-1]>0){ans[i]=k-a[i]+ans[i-1];}
    else if((ans[i-1]+a[i])-k>0 and ans[i-1]>0) {ans[i]=a[i]+ans[i-1]-k;}
    else if((ans[i-1]+a[i])-k>0 and ans[i-1]==0){ans[i]=a[i]-k;}
    }

cout<<ans[n-1]<<endl;
system("pause");
return 0;}

Edited by author 15.11.2012 12:40