include [HTML_REMOVED]

using namespace std;

const int N = 100010;

int n, m;
int a[N], s[N];

int main()
{
scanf(“%d%d”, &n, &m);
for (int i = 1; i <= n; i ++ ) scanf(“%d”, &a[i]);

for (int i = 1; i <= n; i ++ ) s[i] = s[i - 1] + a[i]; // 前缀和的初始化

while (m -- )
{
    int l, r;
    scanf("%d%d", &l, &r);
    printf("%d\n", s[r] - s[l - 1]); // 区间和的计算
}

return 0;

}