const readline = require('readline').createInterface({
    input: process.stdin,
    output: process.stdout
});

const input = [];
readline.on('line', (line) => {
    input.push(line);
});

readline.on('close', () => {
    // 解析基本信息
    const [n, m] = input[0].split(' ').map(Number);
    const sequence = input[1].split(' ').map(Number);

    // 计算前缀和
    const prefixSum = new Array(n + 1).fill(0); //  fill(0) 是初始化数组每一项都是0
    for (let i = 1; i <= n; i++) {
        prefixSum[i] = prefixSum[i - 1] + sequence[i - 1];
    }

    // 处理每个查询
    for (let i = 2; i < 2 + m; i++) {
        const [l, r] = input[i].split(' ').map(Number);
        console.log(prefixSum[r] - prefixSum[l - 1]);
    }
});