URAL 1998 The old Padawan

#include<map>
#include<set>
#include<ctime>
#include<cmath>
#include<queue>
#include<string>
#include<vector>
#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<functional>
using namespace std;
#define ms(x,y) memset(x,y,sizeof(x))
#define rep(i,j,k) for(int i=j;i<=k;i++)
#define per(i,j,k) for(int i=j;i>=k;i--)
#define loop(i,j,k) for (int i=j;i!=-1;i=k[i])
#define inone(x) scanf("%d",&x)
#define intwo(x,y) scanf("%d%d",&x,&y)
#define inthr(x,y,z) scanf("%d%d%d",&x,&y,&z)
#define infou(x,y,z,p) scanf("%d%d%d%d",&x,&y,&z,&p)
#define lson x<<1,l,mid
#define rson x<<1|1,mid+1,r
#define mp(i,j) make_pair(i,j)
#define ft first
#define sd second
typedef long long LL;
typedef pair<int, int> pii;
const int low(int x) { return x&-x; }
const int INF = 0x7FFFFFFF;
const int mod = 1e9 + 7;
const int N = 1e5 + 10;
const int M = 1e4 + 1;
const double eps = 1e-10;

int n,m,k;
int sum[N],a[N],t[N];

int main()
{
    while(~scanf("%d%d%d",&n,&m,&k))
    {
        for(int i=1;i<=n;i++)
        {
            scanf("%d",&a[i]);
            sum[i] = sum[i-1] + a[i];
        }

        for(int i=1;i<=m;i++) scanf("%d",&t[i]);

        int top=0;
        int ans=0;

        for(int i=1;i<=m;i++)
        {
            if(top + t[i]-t[i-1]-1>=n) break;

            top = top + t[i]-t[i-1]-1;

            ans=t[i];

            if(top!=0)
            {
                if(sum[top]<=k)
                {
                    top=0;
                    continue;
                }

                int L=1,R=top,res;
                while(L<=R)
                {
                    int mid = (L+R)/2;
                    if(sum[top]-sum[mid-1]>k) res=mid, L=mid+1;
                    else R=mid-1;
                }

                top=res-1;
            }
        }

        if(top<n) ans=ans+n-top;

        printf("%d\n",ans);

    }
    return 0;
}