#!/usr/bin/env python3
import sys

def expand(dense):
    fs = []
    for i in range(len(dense)):
        if i % 2 == 0:
            for j in range(int(dense[i])):
                fs.append(i // 2)
        else:
            for j in range(int(dense[i])):
                fs.append(None)
    return fs

def pprint(fs):
    for c in fs:
        if c is not None:
            print(c, end="")
        else:
            print(".", end="")
    print("")

def compact(fs):
    comp = [c for c in fs]

    # First store the free space to avoid rescanning every time
    free = {}
    start = None
    size = 0
    for i in range(len(comp)):
        if comp[i] is not None:
            if start is not None:
                free[start] = size
            start = None
            size = 0
        else:
            if start is None:
                start = i
            size += 1

    # work backwards
    id = comp[-1]
    end = len(comp) - 1
    for i in range(len(comp) - 1, -1, -1):
        if comp[i] == id:
            # still in file block
            continue
        else:
            if id is not None:
                # span from i + 1 -> end needs moving
                start = i + 1
                size = end - start + 1
                for f in sorted(free.keys()):
                    if f < start and free[f] >= size:
                        # copy the block
                        for j in range(size):
                            comp[f + j] = comp[start + j]
                            comp[start + j] = None
                        # update our space
                        free[f + size] = free[f] - size
                        del(free[f])
                        break
            # reset state
            id = comp[i]
            end = i
    return comp

def chksum(fs):
    tot = 0
    for i in range(len(fs)):
        if fs[i] is None:
            continue
        tot += fs[i] * i
    
    return tot

if __name__ == '__main__':
    dense = next(sys.stdin).strip()
    fs = expand(dense)
    comp = compact(fs)
    # pprint(comp)
    print(chksum(comp))