Stuck in modify!

I am stuck in the: GNU nano 2.2.2 File: gcc-4.1.1/gcc/config/arm/t-arm-elf Modified part I added the lines as was stated and tried to exit and save but it just says: [ Error writing gcc-4.1.1/gcc/config/arm/t-arm-elf: No such file or directory ]

here is the full layout am I doing something wrong?:

GNU nano 2.2.2 File: gcc-4.1.1/gcc/config/arm/t-arm-elf Modified

MULTILIB_OPTIONS += mno-thumb-interwork/mthumb-interwork
MULTILIB_DIRNAMES += normal interwork
MULTILIB_OPTIONS += mfpu=vfp/mfpu=fpa
MULTILIB_DIRNAMES += vfp fpa

[ Error writing gcc-4.1.1/gcc/config/arm/t-arm-elf: No such file or directory ]
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