#include <bits/stdc++.h>
using namespace std;

#define times(n, i)      uptil(0, n, i)
#define rtimes(n, i)     downto((n) - 1, 0, i)
#define upto(f, t, i)    for(auto i##0_to = (t), i = decltype(t)(f); i <= i##0_to; i++)
#define uptil(f, t, i)   for(auto i##0_to = (t), i = decltype(t)(f); i <  i##0_to; i++)
#define downto(f, t, i)  for(auto i##0_to = decltype(f)(t), i = (f); i >= i##0_to; i--)
#define downtil(f, t, i) for(auto i##0_to = decltype(f)(t), i = (f); i >  i##0_to; i--)
/** types **/
    using LD = long double;
    #define double LD
    #define long long long
    #define LL long
    #define int long
    template<class T> using vec = vector<T>;
    using VB = vec<bool>;   using WB = vec<VB>;
    using VC = vec<char>;   using WC = vec<VC>;
    using VI = vec<int>;    using WI = vec<VI>;
    using VD = vec<double>; using WD = vec<VD>;
    using VS = vec<string>; using WS = vec<VS>;
    using PI = pair<int, int>;  using VPI = vec<PI>; using WPI = vec<VPI>;
    using MI = map<int, int>;   using VMI = vec<MI>;

bool debug;
#define _GLIBCXX_DEBUG
#define _LIBCPP_DEBUG 2
#define _LIBCPP_DEBUG2 2
#define ln << '\n'
#define tb << '\t'
#define sp << ' '
#define DD(x) if(debug) cerr << #x << " = " << (x) << ", "
#define DDD(x) if(debug) cerr << #x << " = " << (x) ln
#define db dd
#define dbg ddd

void settings();
void solve();

signed main(signed argc, char *argv[]) {
    #ifdef EBUG
        debug = true;
    #elif defined(ONLINE_JUDGE)
        debug = false;
    #else
        debug = argc >= 2;
    #endif
    if(!debug) {
        cin.tie(0);
        ios::sync_with_stdio(0);
    }
    cout << fixed << setprecision(20);
    cerr << fixed << setprecision(20);

    settings();
    solve();

    return 0;
}

/******************************* basic library ********************************/
/** structure **/
    template<class T> struct Graph { bool directed = false; int nv = -1; int ne = -1; vec<map<int,T>> e;
        Graph<T> rev() { if(not directed) return *this; Graph<T> g = *this; for(auto& ei : g.e) ei.clear(); times(nv, i) for(auto& p : e[i]) g.e[p.first][i] = p.second; return g; }
    };
    using GraphI = Graph<int>;
/** IO **/
    template<class T> inline istream& operator>>(istream& s, vec<T>& v) { for(auto&& p : v) s >> p; return s; }
    int INPUT_GRAPH_index_sub = 1, INPUT_GRAPH_cost = 0; bool INPUT_GRAPH_allow_empty = false;
    template<class T> inline istream& operator>>(istream& s, Graph<T>& g) {
        const int sub = INPUT_GRAPH_index_sub, cost = INPUT_GRAPH_cost, emptyp = INPUT_GRAPH_allow_empty;
        if(g.nv + emptyp <= 0 and g.ne + emptyp <= 0) { s >> g.nv >> g.ne; } g.e = VMI(g.nv);
        times(g.ne, i) { int x, y; T d = cost; s >> x >> y; if(!d) s >> d; g.e[x - sub][y - sub] = d; if(not g.directed) g.e[y - sub][x - sub] = d; } return s;
    }
    template<class T, class S> inline ostream& operator<<(ostream&, const pair<T, S>&);
    template<class T>          inline ostream& operator<<(ostream&, const vec<T>&);
    template<class T, class S> inline ostream& operator<<(ostream&, const map<T, S>&);
    template<class T> inline ostream& operator<<(ostream&, const Graph<T>&);
    #define DEFINE_ITER_OUTPUT(s, x, sep) { int i = 0; for(const auto& x##0_elem : x) { if(i++) s << sep; s << x##0_elem; } return s; }
    template<class T, class S> inline ostream& operator<<(ostream& s, const pair<T, S>& p) { return s << "(" << p.first << "," << p.second << ")"; }
    template<class T>          inline ostream& operator<<(ostream& s, const vec<T>& v) DEFINE_ITER_OUTPUT(s, v, ' ')
    template<class T, class S> inline ostream& operator<<(ostream& s, const map<T, S>& m) DEFINE_ITER_OUTPUT(s, m, ' ')
    template<class T>          inline ostream& operator<<(ostream& s, const vec<vec<T>>& w) DEFINE_ITER_OUTPUT(s, w, '\n')
    template<class T, class S> inline ostream& operator<<(ostream& s, const vec<map<T, S>>& vm) DEFINE_ITER_OUTPUT(s, vm, '\n')
    template<class T> inline ostream& operator<<(ostream& s, const Graph<T>& g) { return s << "Graph(nv:" << g.nv << " ne:" << g.ne << " e:[" ln << g.e ln << "])"; }
    inline void RD() {}
    template<class T, class...S> inline T& RD(T& t, S&... s) { cin >> t; RD(s...); return t; } /* returns first side */
    template<class T, class...S> inline vec<T>& RD(vec<T>& t, vec<S>&... s) { times(t.size(), i) { RD(t[i], s[i]...); } return t; }
    #define RR(typ, ...) typ __VA_ARGS__; RD(__VA_ARGS__)
    template<class T, class...A> inline T READ(A... a) { T t(a...); cin >> t; return t; }
    template<class T> inline void dddf(const T& t) { if(debug) cerr << t ln; }
    template<class T, class...U> inline void dddf(const T& t, const U&... u) { if(debug) { cerr << t << ", "; dddf(u...); }}
    #define ddd(...) if(debug) { cerr << #__VA_ARGS__ << " = "; dddf(__VA_ARGS__); }
/** container **/
    #define all(v) begin(v), end(v)
    template<class T> inline T max(const pair<T, T>& p) { return max(p.first, p.second); }
    template<class T> inline T min(const pair<T, T>& p) { return min(p.first, p.second); }
    template<class T> inline T max(const vec<T>& v) { return *max_element(all(v)); }
    template<class T> inline T min(const vec<T>& v) { return *min_element(all(v)); }
    template<class T> inline T sum(const vec<T>& v) { T s = v.empty() ? 0 : v[0]; uptil(1, v.size(), i) s += v[i]; return s; }
    template<class T> inline T sum(const vec<T>& v, int mod) { T s = v.empty() ? 0 : v[0]; uptil(1, v.size(), i) (s += v[i]) %= mod; return s; }
    template<class T, class U> inline T dig(const U& d, const T& t) { return t; }
    template<class T, class U, class...I> inline U dig(const U& d, const T& t, int i, I... j) {
        return 0 <= i && i < t.size() ? dig(d, t[i], j...) : d; }
    #define first_itr_st_val_ge_ lower_bound
    #define first_itr_st_val_gt_ upper_bound
/** other **/
    template<class T> inline signed SIZE(const T& t) { return t.size(); }
    #define size SIZE
    #define MP make_pair
    #define MT make_tuple
    #define b_max(x, y) x = max(x, y)
    #define b_min(x, y) x = min(x, y)
    inline LD AC(LD d) { return d ? d : 0; }
[[maybe_unused]] constexpr long INF = 1LL << 60;
[[maybe_unused]] constexpr long MOD = 1000000007; // 1000000009; // 998244353;

/****************************** optional library ******************************/
/* <sr.q.uf> */
    // VERIFIED: arc090b
    // ref: https://github.com/monyone/teihen_library/blob/master/DataStructure/01_WeightedUnionFind.md
    struct UnionFind {
        int n;
        VI parents, treeSizes, weightDiffs;
        UnionFind(int n_) : n(n_), parents(n), treeSizes(n, 1), weightDiffs(n, 0) { times(n, i) parents[i] = i; }
        int root(int i) {
            if(parents[i] == i) return i;
            int p = root(parents[i]);
            weightDiffs[i] += weightDiffs[parents[i]];
            return parents[i] = p;
        }
        int weight(int i) { root(i); return weightDiffs[i]; }
        void merge(int i, int j, int w = 0) { // w > 0 if i < j
            if(same(i, j)) return;
            int x = w + weight(i) - weight(j);
            i = root(i); j = root(j);
            if(treeSizes[i] < treeSizes[j]) { swap(i, j); x = -x; }
            parents[j] = i;
            treeSizes[i] += treeSizes[j]; treeSizes[j] = -1;
            weightDiffs[j] = x;
        }
        bool same(int i, int j) { return root(i) == root(j); }
        int diff(int base, int i) { return same(base, i) ? weight(i) - weight(base) : -INF; }
    };
/* </sr.q.uf> */
/************************************ main ************************************/

void settings() {
    // INPUT_GRAPH_index_sub = 0;       // uncomment if input index is 0-based
    // INPUT_GRAPH_allow_empty = true;  // uncomment to allow empty graph
    INPUT_GRAPH_cost = 1;            // uncomment if all input costs are 1
}

void solve() {
// NMSM(-LR)
/* <foxy.memo-area> */
int N;int M;string S;cin>>N;cin>>M;cin>>S;VI L0(M);VI R0(M);times(M,Ri_0){cin>>L0[Ri_0
];--L0[Ri_0];cin>>R0[Ri_0];}
/* </foxy.memo-area> */
    VI L, R; L.reserve(N); R.reserve(N);
    times(M, i) {
        if(size(R) == 0 or R0[i] >= R[size(R)-1]) {
            L.push_back(L0[i]);
            R.push_back(R0[i]);
        }
    }
    M = size(L); /*!!!!!*/

    VI c(N), rj(N), mnc(N), mxc(N);
    times(N, j) {
        c[j] = (j ? c[j-1] : 0) + (S[j] == '1');
    }

    times(M, i) rj[L[i]] = R[i] - 1;
    times(N, j) {
        rj[j] = max({rj[j], j, j ? rj[j-1] : 0});
        mxc[j] = c[rj[j]];
    }

    ddd(L);ddd(R);
    {
        L.push_back(N); R.push_back(N);
        int r1 = 0, cnt = 0;
        times(M, i) {
            uptil(max(r1, L[i]), R[i], j) {
                cnt += S[j] == '1';
                S[j] = '0';
            }
            int kab = max(0ll, R[i] - L[i+1]);
            int d = max(0ll, cnt - kab);
            cnt -= d;
            ddd(cnt, kab, d);
            downto(R[i]-cnt-1, R[i]-cnt-d, j) S[j] = '1';
            r1 = R[i];
        }
        times(N, j) {
            mnc[j] = (j ? mnc[j-1] : 0) + (S[j] == '1');
        }
    }
    ddd(c); ddd(rj); ddd(mxc); ddd(mnc);

    VI dp, dq; dp.push_back(1);
    times(N, i) {
        dq.resize(mxc[i]+1);
        fill(all(dq), 0);
        upto(mnc[i], mxc[i], j) {
            dq[j] = (dig(0, dp, j-1) + dig(0, dp, j)) % MOD;
        }
        swap(dp, dq);
        ddd(i, dp);
    }
    cout << sum(dp, MOD) ln;
}


Measured memory_bytes: 512