import java.util.*;
import java.io.*;

public class Main {
    static ArrayList<Path>[] graph;
    public static void main(String[] args) throws Exception {
        FastScanner sc = new FastScanner();
        int a = sc.nextInt();
        int b = sc.nextInt();
        int c = sc.nextInt();
        int sum = b * 10 + a;
        int min = Integer.MAX_VALUE;
        for (int i = 0; i <= c; i++) {
            int ans = sum - (c - i) * 10 - i;
            int count = a;
            int mod = ans % 10;
            if (mod != 0) {
                count += 10 - mod;
            }
            if (ans > 0 && i <= count) {
                min = Math.min(ans, min);
            }
        }
        if (min == Integer.MAX_VALUE) {
            System.out.println("Impossible");
        } else {
            System.out.println(min);
        }
    }
    
    static void search(int to, long[] costs, long value) {
        if (costs[to] <= value) {
            return;
        }
        costs[to] = value;
        for (Path p : graph[to]) {
            int next;
            if (p.from == to) {
                next = p.to;
            } else {
                next = p.from;
            }
            search(next, costs, value + p.cost);
        }
    }
    
    static class Path {
        int to;
        int from;
        int cost;
        public Path (int to, int from, int cost) {
            this.to = to;
            this.from = from;
            this.cost = cost;
        }
    }
}

class FastScanner {
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        }else{
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }
    private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
    private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
    public boolean hasNext() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; return hasNextByte();}
    public String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while(isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    public long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return minus ? -n : n;
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
    public int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException();
        return (int) nl;
    }
    public double nextDouble() { return Double.parseDouble(next());
        
    }
}