/*
cat <<EOF >mistaken-paste
*/

#pragma GCC diagnostic ignored "-Wincompatible-pointer-types"
#define _USE_MATH_DEFINES

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <math.h>
#include <time.h>

#define BIG 2000000007
#define VERYBIG 2000000000000007LL

#define MOD 1000000007
#define FOD  998244353
typedef uint64_t ull;
typedef  int64_t sll;

#define N_MAX 1000000
#define M_MAX 200000

#ifdef __cplusplus
#include <queue>
#include <stack>
#include <tuple>
#include <set>
#include <map>
#include <string>

// using namespace std; // HELL
using std::queue;
using std::priority_queue;
using std::stack;
using std::tuple;
using std::set;
using std::map;
using std::vector;
using std::greater;
using std::pair;
using std::string;

#endif

typedef struct {
	int32_t a;
	int32_t b;
} hw;

typedef struct {
	sll a;
	sll b;
} hwll;

typedef struct {
	sll a;
	sll b;
	sll c;
} hwllc;

typedef struct {
	hwll a;
	hwll b;
} linell;

ull n, m;
ull h, w;
ull k;
ull q;
ull vua, vub, vuc, vud, vue, vuf;
sll vsa, vsb, vsc, vsd, vse, vsf;
long double vra, vrb, vrc;
double vda, vdb, vdc;
char ch, dh;

ull umin (ull x, ull y) {
	return (x < y) ? x : y;
}

ull umax (ull x, ull y) {
	return (x > y) ? x : y;
}

sll smin (sll x, sll y) {
	return (x < y) ? x : y;
}

sll smax (sll x, sll y) {
	return (x > y) ? x : y;
}

ull gcd (ull x, ull y) {
	if (x < y) {
		return gcd(y, x);
	} else if (y == 0) {
		return x;
	} else {
		return gcd(y, x % y);
	}
}

ull bitpow (ull a, ull x, ull modulo) {
	ull result = 1;
	while (x) {
		if (x & 1) {
			result *= a;
			result %= modulo;
		}
		x /= 2;
		a = (a * a) % modulo;
	}
	return result;
}

ull divide (ull a, ull b, ull modulo) {
	return (a * bitpow(b, modulo - 2, modulo)) % modulo;
}

ull udiff (ull a, ull b) {
	if (a >= b) {
		return a - b;
	} else {
		return b - a;
	}
}

sll sdiff (sll a, sll b) {
	if (a >= b) {
		return a - b;
	} else {
		return b - a;
	}
}

int bitcount (ull n) {
	int result = 0;
	while (n) {
		if (n & 1) result++;
		n /= 2;
	}
	return result;
}

// double distance (sll x1, sll y1, sll x2, sll y2) {
// 	double xdist2, ydist2, origindist, dist;

// 	xdist2 = (x1 - x2) * (x1 - x2);
// 	ydist2 = (y1 - y2) * (y1 - y2);
// 	return sqrt(xdist2 + ydist2);
// }

int32_t pullcomp (const void *left, const void *right) {
	ull l = *(ull*)left;
	ull r = *(ull*)right;
	if (l < r) {
		return -1;
	}
	if (l > r) {
		return +1;
	}
	return 0;
}

int32_t psllcomp (const void *left, const void *right) {
	sll l = *(sll*)left;
	sll r = *(sll*)right;
	if (l < r) {
		return -1;
	}
	if (l > r) {
		return +1;
	}
	return 0;
}

int32_t pcharcomp (const void *left, const void *right) {
	char l = *(char*)left;
	char r = *(char*)right;
	if (l < r) {
		return -1;
	}
	if (l > r) {
		return +1;
	}
	return 0;
}

int32_t pstrcomp (const void *left, const void *right) {
	char* l = *(char**)left;
	char* r = *(char**)right;

	return strcmp(l, r);
}

int32_t phwllABcomp (const void *left, const void *right) {
	hwll l = *(hwll*)left;
	hwll r = *(hwll*)right;
	if (l.a < r.a) {
		return -1;
	}
	if (l.a > r.a) {
		return +1;
	}
	if (l.b < r.b) {
		return -1;
	}
	if (l.b > r.b) {
		return +1;
	}
	return 0;
}

int32_t phwllREVcomp (const void *left, const void *right) {
	hwll l = *(hwll*)left;
	hwll r = *(hwll*)right;
	if (l.b < r.b) {
		return -1;
	}
	if (l.b > r.b) {
		return +1;
	}
	if (l.a < r.a) {
		return -1;
	}
	if (l.a > r.a) {
		return +1;
	}
	return 0;
}

int32_t ptriplecomp (const void *left, const void *right) {
	hwllc l = *(hwllc*)left;
	hwllc r = *(hwllc*)right;

	if (l.a < r.a) {
		return -1;
	}
	if (l.a > r.a) {
		return +1;
	}
	if (l.b < r.b) {
		return -1;
	}
	if (l.b > r.b) {
		return +1;
	}
	if (l.c < r.c) {
		return -1;
	}
	if (l.c > r.c) {
		return +1;
	}
	return 0;
}

bool isinrange (sll left, sll x, sll right) {
	return (left <= x && x <= right);
}

bool isinrange_soft (sll left, sll x, sll right) {
	return (left <= x && x <= right) || (left >= x && x >= right);
}

ull parent[N_MAX];
ull rank[N_MAX];
void uf_init (ull n) {
	for (sll i = 0; i < n; i++) {
		parent[i] = i;
		rank[i] = 0;
	}
}
ull uf_find (ull x) {
	if (parent[x] == x) return x;
	return parent[x] = uf_find(parent[x]);
}
sll uf_union (ull a, ull b) {
	a = uf_find(a);
	b = uf_find(b);
	if (a == b) return -1;

	if (rank[a] > rank[b]) {
		a ^= (b ^= (a ^= b));
	}

	parent[a] = b;
	if (rank[a] == rank[b]) {
		rank[b]++;
	}

	return b;
}


ull a[N_MAX];
// sll a[3001][3001];
sll b[N_MAX];
// sll b[3001][3001];
sll c[N_MAX];
char s[N_MAX + 1];
// char s[3010][3010];
// char t[N_MAX + 1];
// char t[3010][3010];
// hwll xy[N_MAX];

typedef pair<ull, ull> P;

ull ignores = 0;

P dfs (ull begin, ull end, ull cut) {
	sll i, j;

	ull vmin = BIG;
	for (i = begin; i < end; i++) vmin = umin(vmin, a[i]);

	vector<P> query;
	vector<P> v;

	ull wrem = end - begin;

	i = begin;
	while (i < end && a[i] == vmin) i++;
	while (i < end) {
		j = i;
		while (i < end && a[i] != vmin) i++;
		if (i - j == 1) {
			ignores += (a[j] - vmin);
		} else {
			query.push_back(P(j, i));
			wrem -= (i - j);
		}

		while (i < end && a[i] == vmin) i++;
	}

	for (P x : query) {
		P reted = dfs(x.first, x.second, vmin);
		v.push_back(reted);
	}

	P ret;
	if (vmin == 1) {
		ignores += wrem;

		ull reted = 1;
		for (P x : v) {
			reted *= (x.first * 2 + x.second) % MOD;
			reted %= MOD;
		}
		ret.first = reted;
		ret.second = 0;
	} else if (query.empty()) {
		ull h = vmin - cut;

		ret.first = bitpow(2, h, MOD);
		ret.second = (MOD + bitpow(2, end - begin, MOD) - 2) % MOD;
	} else {
		ull unfix = 1;
		ull whole = 1;
		for (P x : v) {
			unfix *= x.first;
			unfix %= MOD;

			whole *= (x.first * 2 + x.second) % MOD;
			whole %= MOD;
		}

		// printf("%llu*%llu/%llu\n", unfix, bitpow(2, vmin - cut, MOD), bitpow(2, v.size() - 1, MOD));
		// ret.first = divide(unfix * bitpow(2, vmin - cut, MOD) % MOD, bitpow(2, v.size() - 1, MOD), MOD);
		// ret.second = 
		// ( ((MOD + whole - unfix) % MOD) * bitpow(2, wrem, MOD) % MOD )
		// + (MOD - divide(unfix, bitpow(2, v.size() - 1, MOD), MOD) + (unfix * bitpow(2, wrem, MOD) % MOD)) % MOD;
		// printf("%llu + %llu\n", ( ((MOD + whole - unfix) % MOD) * bitpow(2, wrem, MOD) % MOD ), (MOD - divide(unfix, bitpow(2, v.size() - 1, MOD), MOD) + (unfix * bitpow(2, wrem, MOD) % MOD)) % MOD
		// 	);

		ret.first = unfix * bitpow(2, vmin - cut, MOD) % MOD;
		ret.second = (MOD + (whole * bitpow(2, wrem, MOD) % MOD) - (unfix * 2 % MOD)) % MOD;
	}

	// printf("%lld~%lld: %llu/%llu ignores: %llu wrem: %llu : %llu-%llu=%llu v%d\n", begin, end, ret.first, ret.second, ignores, wrem, vmin, cut, vmin - cut, v.size());

	return ret;

}

ull solve () {
	sll i, j, ki, li;
	ull result = 0;
	// sll result = 0;
	double dresult = 0;
	// ull maybe = 0;
	sll maybe = 0;
	// ull sum = 0;
	sll sum = 0;
	sll item;
	ull *dpcell;

	P ret = dfs(0, n, 0);

	result = (ret.first + ret.second) % MOD;
	result = (result * bitpow(2, ignores, MOD)) % MOD;

	printf("%llu\n", result);
	// printf("%.15lf\n", dresult);
	// puts(s);

	return 0;

	success:
	// puts("YES");
	// puts("Yes");
	// printf("%llu\n", result);
	// puts("0");
	puts("Takahashi");
	return 0;

	fail:
	// puts("NO");
	// puts("No");
	// puts("0");
	// puts("-1");
	// puts("-1 -1 -1");
	puts("Aoki");
	return 1;
}

int32_t main (void) {
	int32_t i, j;
	int32_t x, y;

	// scanf("%lf%lf", &vda, &vdb, &vdc);
	// scanf("%lld%lld", &vsa, &vsb, &vsc, &vsd);
	// scanf("%llu%llu", &vua, &vub, &vuc, &vud);
	// scanf("%*llu%*llu");
	// scanf("%llu%llu", &h, &w);
	scanf("%llu", &n, &m);
	// scanf("%llu", &k, &n, &m);
	// scanf("%s", s);
	// scanf("%s", t);
	// scanf("%llu", &q);
	for (i = 0; i < n; i++) {
		// scanf("%lld%lld", &xy[i].a, &xy[i].b);
		scanf("%lld", &a[i]);
		// scanf("%lld", &b[i]);
		// scanf("%lld", &c[i]);
		// scanf("%lld", &t[i]);
		// a[i]--;
		// b[i]--;
		// c[i]--;
	}
	// scanf("%llu%llu", &m, &k);
	// for (i = 0; i < w; i++) {
	// 	scanf("%llu", &b[i]);
	// 	// b[i]--;
	// }
	// scanf("%llu", &q);

	// for (i = 0; i < h; i++) {
	// 	for (j = 0; j < w; j++) {
	// 		scanf("%llu", &a[i][j]);
	// 	}
	// }
	// for (i = 0; i < h; i++) {
	// 	scanf("%s", &s[i]);
	// }

	solve();

	return 0;
}


Measured memory_bytes: 2432