#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define READ_BUFSIZE ( 10000 + 1 )
#define READ_DELIMITER ( " " )


//標準入力取得（１行）

int GetStdin( char* pszStr, int lMaxLen )
{
	int lLen = 0;

    memset( pszStr, 0, lMaxLen );
    if( fgets( pszStr, lMaxLen, stdin ) )
    {
	    lLen = strlen( pszStr );
	    if( lLen >= 1 )
	    {
			if( pszStr[ lLen - 1 ] == 0x0A )
			{
				pszStr[ lLen - 1 ] = 0;
				lLen--;
			}
		}
	}
	
	return( lLen );
}



int main(int argc, char *argv[]) 
{
	char szRead[READ_BUFSIZE] = "";
	//char* psOutbuf[2] = { 0 };

	GetStdin( szRead, READ_BUFSIZE );

	int lSummary = 0;
	for( int i = 0; szRead[i] != 0; i++ )
	{
		//数字の範囲 0x30 ー 0x39
		if( szRead[i] >= '0' && szRead[i] <= '9' )
			lSummary += (int)( szRead[i]-'0' );
	}

	printf( "%d\n", lSummary );
	
	return 0;

}