<?xml version="1.0" encoding="utf-8"?>
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    <context id="From2026-03-02to2026-03-02_cmca_UnitsEachConsistingOfOneShareOfClassCommonStockAndOneHalfOfOneWarrantMember">
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    <context id="From2026-03-02to2026-03-02_cmca_OrdinarySharesClassAParValueMember">
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    <context id="From2026-03-02to2026-03-02_cmca_WarrantsEachWholeWarrantExercisableForOneClassAOrdinaryShareEachAtAnExercisePriceOfDollar11.50PerShareMember">
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        <period>
            <startDate>2026-03-02</startDate>
            <endDate>2026-03-02</endDate>
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    <dei:EntityCentralIndexKey contextRef="From2026-03-02to2026-03-02" id="ixv-387">0001865248</dei:EntityCentralIndexKey>
    <dei:AmendmentFlag contextRef="From2026-03-02to2026-03-02" id="ixv-388">false</dei:AmendmentFlag>
    <dei:CurrentFiscalYearEndDate contextRef="From2026-03-02to2026-03-02" id="ixv-389">--03-31</dei:CurrentFiscalYearEndDate>
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    <dei:DocumentPeriodEndDate contextRef="From2026-03-02to2026-03-02" id="ixv-434">2026-03-02</dei:DocumentPeriodEndDate>
    <dei:EntityRegistrantName contextRef="From2026-03-02to2026-03-02" id="ixv-435">Piermont Valley Acquisition Corp</dei:EntityRegistrantName>
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    <dei:WrittenCommunications contextRef="From2026-03-02to2026-03-02" id="ixv-446">false</dei:WrittenCommunications>
    <dei:SolicitingMaterial contextRef="From2026-03-02to2026-03-02" id="ixv-447">false</dei:SolicitingMaterial>
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      contextRef="From2026-03-02to2026-03-02_cmca_UnitsEachConsistingOfOneShareOfClassCommonStockAndOneHalfOfOneWarrantMember"
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    <dei:TradingSymbol
      contextRef="From2026-03-02to2026-03-02_cmca_UnitsEachConsistingOfOneShareOfClassCommonStockAndOneHalfOfOneWarrantMember"
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      contextRef="From2026-03-02to2026-03-02_cmca_OrdinarySharesClassAParValueMember"
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    <dei:TradingSymbol
      contextRef="From2026-03-02to2026-03-02_cmca_OrdinarySharesClassAParValueMember"
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    <dei:Security12bTitle
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      id="aid_3_0">Warrants, each whole warrant exercisable for one Class A ordinary share, each at an exercise price of $11.50 per share</dei:Security12bTitle>
    <dei:TradingSymbol
      contextRef="From2026-03-02to2026-03-02_cmca_WarrantsEachWholeWarrantExercisableForOneClassAOrdinaryShareEachAtAnExercisePriceOfDollar11.50PerShareMember"
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    <dei:EntityExTransitionPeriod contextRef="From2026-03-02to2026-03-02" id="ixv-457">false</dei:EntityExTransitionPeriod>
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