Build cargo build --release Usage 1. Hex to Limb Conversion 256 Bits 32-bit word ./target/release/u256 32 <HEX> 64-bit word ./target/release/u256 64 <HEX> 384 Bits 32-bit word ./target/release/u381 32 <HEX> 64-bit word ./target/release/u381 64 <HEX> 2. 64 bits to 32 bits limb conversion ./target/release/limb_convert <l_0 l_1 l_2 .. l_n>