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#include <fstream>
using namespace std;
ifstream cin("aib.in");
ofstream cout("aib.out");
int bit[100002], n, m;
void update(int i, int val)
{
while(i <= n)
{
bit[i] += val;
i += i & -i;
}
}
int prefixSum(int i)
{
int sum = 0;
while(i > 0)
{
sum += bit[i];
i -= i & -i;
}
return sum;
}
int rangeSum(int i, int j)
{
return prefixSum(j) - prefixSum(i - 1);
}
int main()
{
int ok, a, b;
cin >> n >> m;
for(int i = 1; i <= n; i++)
{
cin >> a;
update(i, a);
}
for(int i = 1; i <= m; i++)
{
int minn = - 1;
cin >> ok >> a;
if(ok != 2)
cin >> b;
if(ok == 0)
update(a, b);
else if(ok == 1)
cout << rangeSum(a, b) << '\n';
else if(ok == 2)
{
int l = 0, r = n, s = 0;
while(l < r)
{
int mid = (l + r) / 2;
if(prefixSum(mid) == a)
{
minn = mid;
break;
}
else if(prefixSum(mid) < a)
l = mid + 1;
else
r = mid;
}
cout << minn << '\n';
}
}
return 0;
}