div2_C_15.07_ОТКУДА WA на 2м тесте?

#include <iostream>
#include <cmath>
#include <vector>
#include <queue>
#include <algorithm>
#include <string>
#include <stack>
#include <set>
#include <map>
#define pii pair <int,int>
#define vec vector
using namespace std;
using ll = long long;
using ld = long double;
using db = double;
void cv(vector <int> &v){
    for (auto x: v) cout<<x<<' ';
    cout<<"\n";
}

void cvl(vector <ll> &v){
    for (auto x: v) cout<<x<<' ';
    cout<<"\n";
}


void cvv(vector <vector <int> > &v){
    for (auto x: v) cv(x);
    cout<<"\n";
}

void cvb(vector <bool> v){
    for (bool x: v) cout<<x<<' ';
    cout<<"\n";
}

void cvs(vector <string>  v){
    for (auto a: v){
        cout<<a<<"\n";
    }
}

bool sh = 0;

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int t; cin>>t;
    for (int go=0;go<t;++go){
        int c,n,q;
        cin>>n>>c>>q;
        string s; cin>>s;
        vector <pii> bnd  = {  {1, n}   };
        for (int i=0;i<c;++i){
            int l,r; cin>>l>>r;
            //l--; r--;
            bnd.push_back({l,r});
        }
        vector <int> pf(c+1);
        pf[0] = n;
        for (int i=1;i<c+1;++i){
            pf[i] = pf[i-1] + bnd[i].second - bnd[i].first + 1;
        }
        for (int look = 0; look < q; ++look){
            int k; cin>>k;
            while (k > n){
                if (sh) cout<<"k = "<<k<<"\n";
                int L = -1, R = c,M;
                //cout<<"L R = "<<L<<' '<<R<<"\n";
                //cout<<"(L + R) / 2 = "<<((L+R)/2)<<"\n";
                while (L+1<R){

                    M = (L + R) / 2;
                    if (sh) cout<<"M = "<<M<<"\n";
                    if (M == 0 && pf[M] >= k){
                        if (sh) cout<<"R = 0 - here is k\n";
                        R = 0;
                        break;
                    }
                    if (k > pf[M]){
                        if (sh) cout<<"less than k\n";
                        L = M;
                    }
                    else {
                        if (sh) cout<<"<= than k\n";
                        R = M;
                    }
                }
                if (sh) cout<<"R = "<<R<<"\n";
                //k-й символ в R-й ячейке {l,r}
                int id = k;
                if (sh) cout<<"id = "<<id<<"\n";
                if (R > 0){
                    id -= pf[R-1];
                    //id++;
                }
                if (sh) cout<<"id = "<<id<<"\n";
                if (sh) cout<<"bnd[R] = "<<bnd[R].first<<' '<<bnd[R].second<<"\n";
                id = id + bnd[R].first - 1;
                if (sh) cout<<"id = "<<id<<"\n";
                k = id;
            }
            if (sh) cout<<"res k = "<<k<<"\n";
            cout<<s[k-1]<<"\n";
        }

    }
}
/*
1
4 3 3
mark
1 4
5 7
3 8
1
10
12



1
4 3 1
mark
1 4
5 7
3 8
10

1
5 2 12
hello
1 2 3 4 5 6 7 8 9 10 11 12


1
4 3 18
fuck
1 2
4 6
1 9
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
*/