1 m and 1 c cross to dest, leaving 2 each at start.
1 m returns, leaving 3 m/2 c at start, 1 c at dest.
2 c cross, leaving 3 m at start and 3 c at dest.
1 c returns, leaving 3 m/1 c at start and 2 c at dest.
2 m cross, leaving 1 m/1 c at start and 2 m/2 c at dest.
1 m and 1 c return, leaving 2 m/2 c at start and 1 m/1 c at dest.
2 m cross, leaving 2 c at start and 3 m/1 c at dest.
1 c returns, leaving 3 c at start and 3 m at dest.
2 c cross, 1 c returns and the remaining 2 c's cross.