#include <cstdio>
#include <iostream>
using namespace std;
const int M = 20005;
const int N = 31;
#define make make_pair
#define pii pair<int,int>
int read()
{
	int x=0,f=1;char c;
	while((c=getchar())<'0' || c>'9') {if(c=='-') f=-1;}
	while(c>='0' && c<='9') {x=(x<<3)+(x<<1)+(c^48);c=getchar();}
	return x*f;
}
int n,q,a[M],lg[M],f[M][20][N],g[N],tmp[N];pii dp[M][20];
//f[i][j][k]:stand for the max (l+al) can reach from i through 2^j jumps and k delete 
int ask(int l,int r)//ask the l of max (l+al) 
{
	int k=lg[r-l+1];
	return max(dp[l][k],dp[r-(1<<k)+1][k]).second;
}
void init()
{
	for(int j=1;(1<<j)<=n;j++)//st
		for(int i=1;i+(1<<j)-1<=n;i++)
			dp[i][j]=max(dp[i][j-1],dp[i+(1<<j-1)][j-1]);
	for(int i=1;i<=n;i++)
		for(int j=0;j<N;j++)
			f[i][0][j]=min(n,i+a[i]+j);//this "min" is necessary
	for(int j=1;(1<<j)<=n;j++)
		for(int i=1;i<=n;i++)//please don't limit the range of i
			for(int k=0;k<N;k++)
				for(int x=0;x<=k;x++)
				{
					int t=ask(i,f[i][j-1][x]);//find the position
					f[i][j][k]=max(f[i][j][k],f[t][j-1][k-x]);
				}
}
signed main()
{
	n=read();q=read();
	for(int i=1;i<=n;i++)
	{
		a[i]=read();
		dp[i][0]=make(min(n,a[i]+i),i);
		if(i>1) lg[i]=lg[i>>1]+1;
	}
	init();
	while(q--)
	{
		int l=read(),r=read(),k=read(),ans=0;
		if(l==r) {puts("0");continue;}
		if(l+a[l]+k>=r) {puts("1");continue;}
		for(int i=0;i<=k;i++) g[i]=l;
		for(int x=15;x>=0;x--)
		{
			if((1<<x)>n) continue;
			for(int i=0;i<=k;i++) tmp[i]=g[i];
			for(int i=0;i<=k;i++)
			{
				int t=ask(l,g[i]);
				for(int j=0;i+j<=k;j++)
					tmp[i+j]=max(tmp[i+j],f[t][x][j]);
			}
			int fl=0;
			for(int i=0;i<=k;i++)
				if(tmp[i]>=r) fl=1;
			if(fl) continue;
			for(int i=0;i<=k;i++) g[i]=tmp[i];
			ans+=(1<<x);
		}
		printf("%d\n",ans+1);
	}
}