#include <bits/stdc++.h>
#define fi first
#define se second
#define all(v) v.begin() , v.end()
#define sz(v) int(v.size())
#define unq(v) sort(all(v)); v.resize(unique(all(v)) - v.begin());
using namespace std;

typedef long long ll;
typedef pair<int , int> ii;
typedef pair<long long , int> lli;

const int maxN = int(2e6)+7;

int n , m , sum[maxN] , l[maxN] , r[maxN] , t[maxN] , res[maxN];
string s;

void update(int x){
    for (; x <= n ; x += x&-x) t[x]++;
}

int get(int x){
    int ans = 0;
    for (; x >= 1 ; x -= x&-x) ans += t[x];
    return ans;
}

void TH1(){
    for (int i = 1 ; i <= n ; i++) t[i] = 0;
    vector<ii> event , query;
    for (int i = 1 ; i <= n ; i++){
        sum[i] = sum[i - 1];
        if (s[i] == '+') sum[i]++; else sum[i]--;
        event.push_back({sum[i] , i});
    }
    sort(all(event)); reverse(all(event));
    for (int i = 1 ; i <= m ; i++){
        if (l[i] <= r[i]) query.push_back({sum[l[i] - 1] , i});
    }
    sort(all(query)); reverse(all(query));
    for (int i = 0 , j = -1 ; i < sz(query) ; i++){
        while (j + 1 < sz(event) && event[j + 1].fi > query[i].fi){
            j++;
            update(event[j].se);
        }
        int id = query[i].se;
        res[id] = get(r[id]) - get(l[id] - 1);
    }
}

void TH2(){
    for (int i = 1 ; i <= n ; i++) t[i] = 0;
    for (int i = 1 ; i <= n / 2 ; i++){
        swap(s[i] , s[n - i + 1]);
    }
    vector<ii> event , query;
    sum[0] = 0;
    for (int i = 1 ; i <= n ; i++){
        sum[i] = sum[i - 1];
        if (s[i] == '+') sum[i]++; else sum[i]--;
        event.push_back({sum[i] , i});
    }
    sort(all(event)); reverse(all(event));
    for (int i = 1 ; i <= m ; i++){
        if (l[i] > r[i]){
            l[i] = n - l[i] + 1;
            r[i] = n - r[i] + 1;
            query.push_back({sum[l[i] - 1] , i});
        }
    }
    sort(all(query)); reverse(all(query));
    for (int i = 0 , j = -1 ; i < sz(query) ; i++){
        while (j + 1 < sz(event) && event[j + 1].fi > query[i].fi){
            j++;
            update(event[j].se);
        }
        int id = query[i].se;
        res[id] = get(r[id]) - get(l[id] - 1);
    }
}

void solve(){
    cin >> n >> m >> s;
    s = '#' + s;
    for (int i = 1 ; i <= m ; i++) cin >> l[i] >> r[i];
    TH1();
    TH2();
    for (int i = 1 ; i <= m ; i++){
        cout << res[i] << "\n";
    }
}

#define name "A"

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    if (fopen(name".INP" , "r")){
        freopen(name".INP" , "r" , stdin);
        freopen(name".OUT" , "w" , stdout);
    }
    int t = 1; //cin >> t;
    while (t--) solve();
    return 0;
}