import java.io.*; import java.util.*; public class Main{ public void solve(){ int A = nextInt(); int B = nextInt(); int S = nextInt(); if(Math.abs(A - S) <= Math.abs(B - S)){ out.println(Math.abs(A - S) + S); }else if(A == 0){ out.println(Math.abs(B - S) + S - 1 + 2); }else{ int a1 = Math.abs(B - S) + Math.abs(A - B) + A; int a2 = Math.abs(B - S) + S - 1 + A; out.println(Math.min(a2, a1)); } } public boolean check(String str, int idx){ if(idx + 3 >= str.length()) return false; if(str.charAt(idx) != 'i') return false; if(str.charAt(idx + 1) != 'w') return false; if(str.charAt(idx + 2) != 'i') return false; return true; } private static PrintWriter out; public static void main(String[] args){ out = new PrintWriter(System.out); new Main().solve(); out.flush(); } public static int nextInt(){ int num = 0; String str = next(); boolean minus = false; int i = 0; if(str.charAt(0) == '-'){ minus = true; i++; } int len = str.length(); for(;i < len; i++){ char c = str.charAt(i); if(!('0' <= c && c <= '9')) throw new RuntimeException(); num = num * 10 + (c - '0'); } return minus ? -num : num; } public static long nextLong(){ long num = 0; String str = next(); boolean minus = false; int i = 0; if(str.charAt(0) == '-'){ minus = true; i++; } int len = str.length(); for(;i < len; i++){ char c = str.charAt(i); if(!('0' <= c && c <= '9')) throw new RuntimeException(); num = num * 10l + (c - '0'); } return minus ? -num : num; } public static String next(){ int c; while(!isAlNum(c = read())){} StringBuilder build = new StringBuilder(); build.append((char)c); while(isAlNum(c = read())){ build.append((char)c); } return build.toString(); } private static byte[] inputBuffer = new byte[1024]; private static int bufferLength = 0; private static int bufferIndex = 0; private static int read(){ if(bufferLength < 0) throw new RuntimeException(); if(bufferIndex >= bufferLength){ try{ bufferLength = System.in.read(inputBuffer); bufferIndex = 0; }catch(IOException e){ throw new RuntimeException(e); } if(bufferLength <= 0) return (bufferLength = -1); } return inputBuffer[bufferIndex++]; } private static boolean isAlNum(int c){ return '!' <= c && c <= '~'; } }