func_code_string: #include <bits/stdc++.h>   int n, m, k, flag, ans, cnt, p, q, w[1000005], f[1000005], g[1000005],       s[1000005];   int main() {     scanf( %d%d%d , &n, &m, &k);     w[0] = 1;     for (int i = 1; i <= n; i++) w[i] = w[i - 1] * 2 % 1000000007;     for (int i = 1; i <= m; i++) {       int x, y;       scanf( %d%d , &x, &y);       if (x > y) std::swap(x, y);       if (x + 1 == y)         f[x] = 1;       else if (x + k + 1 == y)         g[x] = 1, ++cnt;       else         flag = 1;     }     if (flag) {       puts( 0 );       return 0;     }     if (cnt == 0) {       for (int i = 1; i <= n; i++) {         if (i + k + 1 > n) continue;         int up = (i + k + k + 1 > n ? n - k - 1 : i + k);         int can = up - i + 1;         ans = (ans + w[can - 1]) % 1000000007;       }       ++ans;       printf( %d n , ans);       return 0;     }     for (int i = 1; i <= n; i++)       if (g[i]) q = i;     for (int i = n; i >= 1; i--)       if (g[i]) p = i;     if (p + k + 1 <= q) {       puts( 0 );       return 0;     }     for (int i = 1; i <= n; i++) s[i] = s[i - 1] + g[i];     for (int i = 1; i <= n; i++) {       if (g[i] || i + k + 1 > n) continue;       if (i >= p + k + 1 || i + k + 1 <= q) continue;       int cp = p, cq = q;       if (i < p) p = i;       if (i > q) q = i;       int up = (p + k + k + 1 > n ? n - k - 1 : p + k);       int can = up - i + 1 - (s[up] - s[i - 1]);       ans = (ans + w[can - 1]) % 1000000007;       q = cq, p = cp;     }     ++ans;     printf( %d n , ans);   }   