package contest171124; import java.io.ByteArrayInputStream; import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; import java.util.Arrays; import java.util.InputMismatchException; public class C { InputStream is; PrintWriter out; String INPUT = ""; void solve() { char[] s = ns().toCharArray(); int n = s.length; int[] sa = sa(s); int[] lcp = buildLCP(s, sa); // SegmentTreeRMQ st = new SegmentTreeRMQ(lcp); int[][] st = build(lcp); int[] isa = new int[n]; for(int i = 0;i < n;i++)isa[sa[i]] = i; int mod = 1000000007; long[] dp = new long[(n-1)/2+2]; dp[(n-1)/2+1] = 1; for(int i = (n-1)/2;i >= 0;i--){ dp[i]++; for(int len = 1;len*2 <= n-i*2;len++){ int j = n-i-len; int ii = isa[i], ij = isa[j]; // int llcp = st.minx(Math.min(ii, ij) + 1, Math.max(ii, ij) + 1); int llcp = rmq(st, Math.min(ii, ij) + 1, Math.max(ii, ij) + 1); if(llcp >= len){ dp[i] += dp[i+len]; } } dp[i] %= mod; } out.println(dp[0]); } public static int[][] build(int[] a) { int n = a.length; int b = 32-Integer.numberOfLeadingZeros(n); int[][] ret = new int[b][]; for(int i = 0, l = 1;i < b;i++, l*=2) { if(i == 0) { ret[i] = a; }else { ret[i] = new int[n-l+1]; for(int j = 0;j < n-l+1;j++) { ret[i][j] = Math.min(ret[i-1][j], ret[i-1][j+l/2]); } } } return ret; } // [a,b) public static int rmq(int[][] or, int l, int r) { assert l <= r; if(l >= r)return Integer.MAX_VALUE; // 1:0, 2:1, 3:1, 4:2, 5:2, 6:2, 7:2, 8:3 int t = 31-Integer.numberOfLeadingZeros(r-l); return Math.min(or[t][l], or[t][r-(1<>>1; st = new int[M]; Arrays.fill(st, 0, M, Integer.MAX_VALUE); } public SegmentTreeRMQ(int[] a) { N = a.length; M = Integer.highestOneBit(Math.max(N-1, 1))<<2; H = M>>>1; st = new int[M]; for(int i = 0;i < N;i++){ st[H+i] = a[i]; } Arrays.fill(st, H+N, M, Integer.MAX_VALUE); for(int i = H-1;i >= 1;i--)propagate(i); } public void update(int pos, int x) { st[H+pos] = x; for(int i = (H+pos)>>>1;i >= 1;i >>>= 1)propagate(i); } private void propagate(int i) { st[i] = Math.min(st[2*i], st[2*i+1]); } public int minx(int l, int r){ int min = Integer.MAX_VALUE; if(l >= r)return min; while(l != 0){ int f = l&-l; if(l+f > r)break; int v = st[(H+l)/f]; if(v < min)min = v; l += f; } while(l < r){ int f = r&-r; int v = st[(H+r)/f-1]; if(v < min)min = v; r -= f; } return min; } public int min(int l, int r){ return l >= r ? 0 : min(l, r, 0, H, 1);} private int min(int l, int r, int cl, int cr, int cur) { if(l <= cl && cr <= r){ return st[cur]; }else{ int mid = cl+cr>>>1; int ret = Integer.MAX_VALUE; if(cl < r && l < mid){ ret = Math.min(ret, min(l, r, cl, mid, 2*cur)); } if(mid < r && l < cr){ ret = Math.min(ret, min(l, r, mid, cr, 2*cur+1)); } return ret; } } public int firstle(int l, int v) { int cur = H+l; while(true){ if(st[cur] <= v){ if(cur < H){ cur = 2*cur; }else{ return cur-H; } }else{ cur++; if((cur&cur-1) == 0)return -1; if((cur&1)==0)cur>>>=1; } } } public int lastle(int l, int v) { int cur = H+l; while(true){ if(st[cur] <= v){ if(cur < H){ cur = 2*cur+1; }else{ return cur-H; } }else{ if((cur&cur-1) == 0)return -1; cur--; if((cur&1)==1)cur>>>=1; } } } } private static interface BaseArray { public int get(int i); public void set(int i, int val); public int update(int i, int val); } private static class CharArray implements BaseArray { private char[] m_A = null; private int m_pos = 0; CharArray(char[] A, int pos) { m_A = A; m_pos = pos; } public int get(int i) { return m_A[m_pos + i] & 0xffff; } public void set(int i, int val) { m_A[m_pos + i] = (char) (val & 0xffff); } public int update(int i, int val) { return m_A[m_pos + i] += val & 0xffff; } } private static class IntArray implements BaseArray { private int[] m_A = null; private int m_pos = 0; IntArray(int[] A, int pos) { m_A = A; m_pos = pos; } public int get(int i) { return m_A[m_pos + i]; } public void set(int i, int val) { m_A[m_pos + i] = val; } public int update(int i, int val) { return m_A[m_pos + i] += val; } } /* find the start or end of each bucket */ private static void getCounts(BaseArray T, BaseArray C, int n, int k) { int i; for(i = 0;i < k;++i){ C.set(i, 0); } for(i = 0;i < n;++i){ C.update(T.get(i), 1); } } private static void getBuckets(BaseArray C, BaseArray B, int k, boolean end) { int i, sum = 0; if(end != false){ for(i = 0;i < k;++i){ sum += C.get(i); B.set(i, sum); } }else{ for(i = 0;i < k;++i){ sum += C.get(i); B.set(i, sum - C.get(i)); } } } /* sort all type LMS suffixes */ private static void LMSsort(BaseArray T, int[] SA, BaseArray C, BaseArray B, int n, int k) { int b, i, j; int c0, c1; /* compute SAl */ if(C == B){ getCounts(T, C, n, k); } getBuckets(C, B, k, false); /* find starts of buckets */ j = n - 1; b = B.get(c1 = T.get(j)); --j; SA[b++] = (T.get(j) < c1) ? ~j : j; for(i = 0;i < n;++i){ if(0 < (j = SA[i])){ if((c0 = T.get(j)) != c1){ B.set(c1, b); b = B.get(c1 = c0); } --j; SA[b++] = (T.get(j) < c1) ? ~j : j; SA[i] = 0; }else if(j < 0){ SA[i] = ~j; } } /* compute SAs */ if(C == B){ getCounts(T, C, n, k); } getBuckets(C, B, k, true); /* find ends of buckets */ for(i = n - 1, b = B.get(c1 = 0);0 <= i;--i){ if(0 < (j = SA[i])){ if((c0 = T.get(j)) != c1){ B.set(c1, b); b = B.get(c1 = c0); } --j; SA[--b] = (T.get(j) > c1) ? ~(j + 1) : j; SA[i] = 0; } } } private static int LMSpostproc(BaseArray T, int[] SA, int n, int m) { int i, j, p, q, plen, qlen, name; int c0, c1; boolean diff; /* * compact all the sorted substrings into the first m items of SA 2*m * must be not larger than n (proveable) */ for(i = 0;(p = SA[i]) < 0;++i){ SA[i] = ~p; } if(i < m){ for(j = i, ++i;;++i){ if((p = SA[i]) < 0){ SA[j++] = ~p; SA[i] = 0; if(j == m){ break; } } } } /* store the length of all substrings */ i = n - 1; j = n - 1; c0 = T.get(n - 1); do{ c1 = c0; }while ((0 <= --i) && ((c0 = T.get(i)) >= c1)); for(;0 <= i;){ do{ c1 = c0; }while ((0 <= --i) && ((c0 = T.get(i)) <= c1)); if(0 <= i){ SA[m + ((i + 1) >> 1)] = j - i; j = i + 1; do{ c1 = c0; }while ((0 <= --i) && ((c0 = T.get(i)) >= c1)); } } /* find the lexicographic names of all substrings */ for(i = 0, name = 0, q = n, qlen = 0;i < m;++i){ p = SA[i]; plen = SA[m + (p >> 1)]; diff = true; if((plen == qlen) && ((q + plen) < n)){ for(j = 0;(j < plen) && (T.get(p + j) == T.get(q + j));++j){ } if(j == plen){ diff = false; } } if(diff != false){ ++name; q = p; qlen = plen; } SA[m + (p >> 1)] = name; } return name; } /* compute SA and BWT */ private static void induceSA(BaseArray T, int[] SA, BaseArray C, BaseArray B, int n, int k) { int b, i, j; int c0, c1; /* compute SAl */ if(C == B){ getCounts(T, C, n, k); } getBuckets(C, B, k, false); /* find starts of buckets */ j = n - 1; b = B.get(c1 = T.get(j)); SA[b++] = ((0 < j) && (T.get(j - 1) < c1)) ? ~j : j; for(i = 0;i < n;++i){ j = SA[i]; SA[i] = ~j; if(0 < j){ if((c0 = T.get(--j)) != c1){ B.set(c1, b); b = B.get(c1 = c0); } SA[b++] = ((0 < j) && (T.get(j - 1) < c1)) ? ~j : j; } } /* compute SAs */ if(C == B){ getCounts(T, C, n, k); } getBuckets(C, B, k, true); /* find ends of buckets */ for(i = n - 1, b = B.get(c1 = 0);0 <= i;--i){ if(0 < (j = SA[i])){ if((c0 = T.get(--j)) != c1){ B.set(c1, b); b = B.get(c1 = c0); } SA[--b] = ((j == 0) || (T.get(j - 1) > c1)) ? ~j : j; }else{ SA[i] = ~j; } } } /* * find the suffix array SA of T[0..n-1] in {0..k-1}^n use a working space * (excluding T and SA) of at most 2n+O(1) for a constant alphabet */ private static void SA_IS(BaseArray T, int[] SA, int fs, int n, int k) { BaseArray C, B, RA; int i, j, b, m, p, q, name, newfs; int c0, c1; int flags = 0; if(k <= 256){ C = new IntArray(new int[k], 0); if(k <= fs){ B = new IntArray(SA, n + fs - k); flags = 1; }else{ B = new IntArray(new int[k], 0); flags = 3; } }else if(k <= fs){ C = new IntArray(SA, n + fs - k); if(k <= (fs - k)){ B = new IntArray(SA, n + fs - k * 2); flags = 0; }else if(k <= 1024){ B = new IntArray(new int[k], 0); flags = 2; }else{ B = C; flags = 8; } }else{ C = B = new IntArray(new int[k], 0); flags = 4 | 8; } /* * stage 1: reduce the problem by at least 1/2 sort all the * LMS-substrings */ getCounts(T, C, n, k); getBuckets(C, B, k, true); /* find ends of buckets */ for(i = 0;i < n;++i){ SA[i] = 0; } b = -1; i = n - 1; j = n; m = 0; c0 = T.get(n - 1); do{ c1 = c0; }while ((0 <= --i) && ((c0 = T.get(i)) >= c1)); for(;0 <= i;){ do{ c1 = c0; }while ((0 <= --i) && ((c0 = T.get(i)) <= c1)); if(0 <= i){ if(0 <= b){ SA[b] = j; } b = B.update(c1, -1); j = i; ++m; do{ c1 = c0; }while ((0 <= --i) && ((c0 = T.get(i)) >= c1)); } } if(1 < m){ LMSsort(T, SA, C, B, n, k); name = LMSpostproc(T, SA, n, m); }else if(m == 1){ SA[b] = j + 1; name = 1; }else{ name = 0; } /* * stage 2: solve the reduced problem recurse if names are not yet * unique */ if(name < m){ if((flags & 4) != 0){ C = null; B = null; } if((flags & 2) != 0){ B = null; } newfs = (n + fs) - (m * 2); if((flags & (1 | 4 | 8)) == 0){ if((k + name) <= newfs){ newfs -= k; }else{ flags |= 8; } } for(i = m + (n >> 1) - 1, j = m * 2 + newfs - 1;m <= i;--i){ if(SA[i] != 0){ SA[j--] = SA[i] - 1; } } RA = new IntArray(SA, m + newfs); SA_IS(RA, SA, newfs, m, name); RA = null; i = n - 1; j = m * 2 - 1; c0 = T.get(n - 1); do{ c1 = c0; }while ((0 <= --i) && ((c0 = T.get(i)) >= c1)); for(;0 <= i;){ do{ c1 = c0; }while ((0 <= --i) && ((c0 = T.get(i)) <= c1)); if(0 <= i){ SA[j--] = i + 1; do{ c1 = c0; }while ((0 <= --i) && ((c0 = T.get(i)) >= c1)); } } for(i = 0;i < m;++i){ SA[i] = SA[m + SA[i]]; } if((flags & 4) != 0){ C = B = new IntArray(new int[k], 0); } if((flags & 2) != 0){ B = new IntArray(new int[k], 0); } } /* stage 3: induce the result for the original problem */ if((flags & 8) != 0){ getCounts(T, C, n, k); } /* put all left-most S characters into their buckets */ if(1 < m){ getBuckets(C, B, k, true); /* find ends of buckets */ i = m - 1; j = n; p = SA[m - 1]; c1 = T.get(p); do{ q = B.get(c0 = c1); while (q < j){ SA[--j] = 0; } do{ SA[--j] = p; if(--i < 0){ break; } p = SA[i]; }while ((c1 = T.get(p)) == c0); }while (0 <= i); while (0 < j){ SA[--j] = 0; } } induceSA(T, SA, C, B, n, k); C = null; B = null; } /* char */ public static void suffixsort(char[] T, int[] SA, int n) { if((T == null) || (SA == null) || (T.length < n) || (SA.length < n)){ return; } if(n <= 1){ if(n == 1){ SA[0] = 0; } return; } SA_IS(new CharArray(T, 0), SA, 0, n, 128); } public static int[] sa(char[] T) { int n = T.length; int[] sa = new int[n]; suffixsort(T, sa, n); return sa; } public static int[] buildLCP(char[] str, int[] sa) { int n = str.length; int h = 0; int[] lcp = new int[n]; int[] isa = new int[n]; for(int i = 0;i < n;i++)isa[sa[i]] = i; for(int i = 0;i < n;i++){ if(isa[i] > 0){ for(int j = sa[isa[i]-1]; j+h 0)h--; } return lcp; } void run() throws Exception { is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes()); out = new PrintWriter(System.out); long s = System.currentTimeMillis(); solve(); out.flush(); if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms"); // Thread t = new Thread(null, null, "~", Runtime.getRuntime().maxMemory()){ // @Override // public void run() { // long s = System.currentTimeMillis(); // solve(); // out.flush(); // if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms"); // } // }; // t.start(); // t.join(); } public static void main(String[] args) throws Exception { new C().run(); } private byte[] inbuf = new byte[1024]; public int lenbuf = 0, ptrbuf = 0; private int readByte() { if(lenbuf == -1)throw new InputMismatchException(); if(ptrbuf >= lenbuf){ ptrbuf = 0; try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); } if(lenbuf <= 0)return -1; } return inbuf[ptrbuf++]; } private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); } private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; } private double nd() { return Double.parseDouble(ns()); } private char nc() { return (char)skip(); } private String ns() { int b = skip(); StringBuilder sb = new StringBuilder(); while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ') sb.appendCodePoint(b); b = readByte(); } return sb.toString(); } private char[] ns(int n) { char[] buf = new char[n]; int b = skip(), p = 0; while(p < n && !(isSpaceChar(b))){ buf[p++] = (char)b; b = readByte(); } return n == p ? buf : Arrays.copyOf(buf, p); } private int[] na(int n) { int[] a = new int[n]; for(int i = 0;i < n;i++)a[i] = ni(); return a; } private long[] nal(int n) { long[] a = new long[n]; for(int i = 0;i < n;i++)a[i] = nl(); return a; } private char[][] nm(int n, int m) { char[][] map = new char[n][]; for(int i = 0;i < n;i++)map[i] = ns(m); return map; } private int[][] nmi(int n, int m) { int[][] map = new int[n][]; for(int i = 0;i < n;i++)map[i] = na(m); return map; } private int ni() { return (int)nl(); } private long nl() { long num = 0; int b; boolean minus = false; while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')); if(b == '-'){ minus = true; b = readByte(); } while(true){ if(b >= '0' && b <= '9'){ num = num * 10 + (b - '0'); }else{ return minus ? -num : num; } b = readByte(); } } private static void tr(Object... o) { System.out.println(Arrays.deepToString(o)); } }