import sys

def main():
    raw_line = sys.stdin.read().strip()
    line = [int(x) for x in raw_line]

    files_map = []
    file_id = 0
    is_file_len = True
    for num in line:
        if is_file_len:
            if num > 0:
                files_map.extend([str(file_id)] * num)
                file_id += 1
        else:
            if num > 0:
                files_map.extend(["."] * num)
        is_file_len = not is_file_len

    map_list = files_map
    while True:
        try:
            gap_index = map_list.index(".")
        except ValueError:
            break
        if all(x == "." for x in map_list[gap_index+1:]):
            break
        rightmost_file_index = None
        for idx in range(len(map_list)-1, -1, -1):
            if map_list[idx] != ".":
                rightmost_file_index = idx
                break
        map_list[gap_index] = map_list[rightmost_file_index]
        map_list[rightmost_file_index] = "."

    checksum_parts = []
    for idx, val in enumerate(map_list):
        if val != ".":
            checksum_parts.append(idx * int(val))
    print("System Checksum Found: " + str(sum(checksum_parts)))

if __name__ == "__main__":
    main()